WO2020090927A1 - Binder composition for secondary battery and method for manufacturing same, slurry composition for secondary battery, functional layer for secondary battery and method for manufacturing same, electrode layer for secondary battery, and secondary battery - Google Patents

Binder composition for secondary battery and method for manufacturing same, slurry composition for secondary battery, functional layer for secondary battery and method for manufacturing same, electrode layer for secondary battery, and secondary battery Download PDF

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Publication number
WO2020090927A1
WO2020090927A1 PCT/JP2019/042659 JP2019042659W WO2020090927A1 WO 2020090927 A1 WO2020090927 A1 WO 2020090927A1 JP 2019042659 W JP2019042659 W JP 2019042659W WO 2020090927 A1 WO2020090927 A1 WO 2020090927A1
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Prior art keywords
secondary battery
group
polymer
mass
slurry composition
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PCT/JP2019/042659
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French (fr)
Japanese (ja)
Inventor
祐輔 足立
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日本ゼオン株式会社
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Priority to CN201980068834.7A priority Critical patent/CN113169334A/en
Priority to JP2020554001A priority patent/JP7468352B2/en
Priority to KR1020217011758A priority patent/KR20210080387A/en
Publication of WO2020090927A1 publication Critical patent/WO2020090927A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/621—Binders
    • H01M4/622—Binders being polymers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/443—Particulate material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/04—Processes of manufacture in general
    • H01M4/0402—Methods of deposition of the material
    • H01M4/0416—Methods of deposition of the material involving impregnation with a solution, dispersion, paste or dry powder
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/04—Processes of manufacture in general
    • H01M4/0471—Processes of manufacture in general involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/139—Processes of manufacture
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/403—Manufacturing processes of separators, membranes or diaphragms
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/411—Organic material
    • H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/021—Physical characteristics, e.g. porosity, surface area
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present invention relates to a binder composition for a secondary battery and a manufacturing method thereof, a slurry composition for a secondary battery, a functional layer for a secondary battery and a manufacturing method thereof, an electrode layer for a secondary battery, and a secondary battery. ..
  • a non-aqueous secondary battery such as a lithium ion secondary battery (hereinafter, may be abbreviated as “secondary battery”) has a characteristic that it is small and lightweight, has a high energy density, and can be repeatedly charged and discharged. It is used for a wide range of purposes.
  • the secondary battery generally includes electrodes (a positive electrode and a negative electrode) having an electrode layer, and a battery member such as a separator that separates the positive electrode and the negative electrode to prevent a short circuit between the positive electrode and the negative electrode.
  • a battery member having a porous membrane layer for the purpose of improving heat resistance and strength and an adhesive layer for improving the adhesiveness between battery members has been used.
  • a binder having a binding property is used for the purpose of adhering the above-mentioned components in the battery member or the battery members to each other. Then, in order to further improve the performance of the secondary battery, it is used for forming electrode layers such as electrode mixture layers (positive electrode mixture layer, negative electrode mixture layer), porous membrane layers, and functional layers such as adhesive layers. Attempts have been made to improve the binder (see, for example, Patent Documents 1 to 3).
  • Patent Document 1 by using a slurry for an electricity storage device containing a water-soluble polymer containing a repeating unit derived from (meth) acrylamide, it is possible to form a layer having excellent adhesion to a current collector or a separator. A technique for manufacturing an electricity storage device having excellent charge / discharge characteristics has been proposed.
  • Patent Document 2 by using a slurry for an electricity storage device electrode containing a water-soluble polymer containing a repeating unit derived from (meth) acrylamide, an active material having a predetermined size, and a liquid medium, current collection is performed.
  • Patent Document 3 water-soluble obtained by polymerizing a monomer group including (i) a polymerizable monomer of an unsaturated carboxylic acid, (ii) (meth) acrylamide, and (iii) a vinyl monomer.
  • Sufficient adhesion to a metal current collector can be obtained by using an acrylic water dispersion for an electrochemical cell containing a resin (a) and organic particles (b) obtained by emulsion-polymerizing a vinyl monomer.
  • a technique which has electrochemical stability and is electrochemically stable, and which does not cause swelling of the electrochemical cell and maintains the conventional electrostatic capacity and internal resistance, and particularly improves the cycle characteristics of the secondary battery.
  • the present inventor has conducted earnest studies for the purpose of providing a binder composition for a secondary battery capable of producing a secondary battery having excellent cycle characteristics. Therefore, the present inventor has conducted extensive studies and found that a secondary battery having excellent cycle characteristics can be produced by using a binder composition containing a predetermined polymer A and a solvent, and completed the present invention.
  • the binder composition for secondary batteries of this invention is a binder for secondary batteries containing the water-soluble polymer A and a solvent.
  • R 1 represents a chemical single bond, a methylene group, an ethylene group, a 1,2-propylene group, or a 1,3-propylene group
  • R 2 and R 3 are each independently.
  • the secondary battery containing the solvent and the polymer A containing the amide group-containing monomer unit, the acid functional group-containing monomer unit, and the monomer unit represented by the general formula (1).
  • containing a monomer unit means "a repeating unit derived from a monomer is contained in a polymer obtained by using the monomer”.
  • the “water-soluble polymer” has an insoluble content in the polymer solid content of less than 30% by mass when 0.5 g of the polymer is dissolved in 100 g of water at a temperature of 90 ° C.
  • the ratio of the monomer unit formed by polymerizing a certain monomer in the polymer is not particularly specified. As long as it is, the ratio (feeding ratio) of the monomer to all the monomers used for the polymerization of the polymer is almost the same.
  • “content ratio of amide group-containing monomer unit”, “content ratio of acid functional group-containing monomer unit” and “content ratio of monomer unit represented by general formula (1)” can be measured using a nuclear magnetic resonance (NMR) method such as 1 H-NMR.
  • the binder composition for a secondary battery of the present invention further contains a compound X represented by the following general formula (2), and the content ratio of the compound X to the solid content of the polymer A is 100 mass ppm or more. Is preferred.
  • X represents a hydrogen atom or an alkali metal atom
  • R 4 represents an alkyl group having 1 to 5 carbon atoms.
  • “content ratio of the compound X with respect to the solid content of the polymer A” can be measured using a high performance liquid chromatograph (HPLC).
  • the weight average molecular weight of the polymer A is preferably 1,000,000 or more.
  • the weight average molecular weight of the polymer A is 1,000,000 or more, the bulk strength of the functional layer formed using the binder composition can be improved and the peel strength can be improved.
  • the “weight average molecular weight of the polymer A” can be measured by the method described in Examples.
  • the electrolytic solution swelling degree of the polymer A is 100% by mass or more and 150% by mass or less.
  • the electrolytic solution swelling degree of the polymer A is 100% by mass or more and 150% by mass or less, a secondary battery having excellent cycle characteristics can be reliably manufactured.
  • the “degree of swelling of polymer A in an electrolytic solution” can be measured by immersing a film of polymer A in an electrolytic solution and measuring a mass increase rate before and after the immersion. More specifically, the “degree of electrolyte solution swelling of the polymer A” can be measured by the method described in Examples.
  • the polymer A contains 20% by mass or more and 60% by mass or less of the amide group-containing monomer unit and 10% by weight of the acid functional group-containing monomer unit. It is preferable that the content of the monomer unit represented by the general formula (1) is 5% by mass or more and 40% by mass or less.
  • Polymer A contains amide group-containing monomer units in an amount of 20% by mass or more and 60% by mass or less, and acid functional group-containing monomer units in an amount of 10% by mass or more and 45% by mass or less, and is represented by the general formula (1).
  • the content of the monomer unit is 5% by mass or more and 40% by mass or less, the viscosity of the slurry composition for a secondary battery is suppressed, the peel strength is improved, and the cycle characteristics of the obtained secondary battery are further improved. be able to.
  • the polymer B of an aqueous dispersion type is further included, and the polymer B contains an aliphatic conjugated diene monomer unit in an amount of 10% by mass or more and 90% by mass or less, It is preferable that the aromatic monomer unit is contained in an amount of 10% by mass or more and 90% by mass or less.
  • the polymer B further comprises an aqueous dispersion type polymer B, and the polymer B contains 10% by mass or more and 90% by mass or less of an aliphatic conjugated diene monomer unit and 10% by mass or more and 90% by mass or less of an aromatic monomer unit. If included, the peel strength can be improved and the cycle characteristics of the obtained secondary battery can be further improved.
  • the “water-dispersion type polymer” has an insoluble content of 30% by mass or more in the polymer solid content when 0.5 g of the polymer is dissolved in 100 g of water at a temperature of 90 ° C. Means a polymer.
  • the “content ratio of the aliphatic conjugated diene monomer unit” and the “content ratio of the aromatic monomer unit” are measured by a nuclear magnetic resonance (NMR) method such as 1 H-NMR. can do.
  • the slurry composition for secondary batteries of this invention contains the binder composition for secondary batteries in any one of the above. Characterize. As described above, by using the slurry composition for a secondary battery containing any one of the binder compositions for a secondary battery described above, a secondary battery having excellent cycle characteristics can be manufactured.
  • the secondary battery slurry composition of the present invention may further include non-conductive fine particles.
  • the secondary battery slurry composition of the present invention may further include an electrode active material.
  • the functional layer for secondary batteries of this invention is a slurry composition for secondary batteries of any one of the above-mentioned on a base material. It is characterized by being formed using.
  • the secondary battery having the functional layer for a secondary battery formed by using the slurry composition for a secondary battery described above on the base material has excellent cycle characteristics.
  • the secondary battery electrode layer of this invention WHEREIN: The slurry for secondary batteries which further contains an electrode active material on a collector. It is characterized by being formed using the composition. As described above, the secondary battery having the secondary battery electrode layer formed by using the above-described secondary battery slurry composition on the current collector has excellent cycle characteristics.
  • the secondary battery of the present invention is a secondary battery comprising a positive electrode, a negative electrode, a separator and an electrolytic solution, the positive electrode, At least one of the negative electrode and the separator has the functional layer for a secondary battery described above.
  • the positive electrode, the negative electrode, and the separator since at least one of the positive electrode, the negative electrode, and the separator has the above-described functional layer for secondary battery, it is possible to provide a secondary battery having excellent cycle characteristics.
  • the manufacturing method of the binder composition for secondary batteries of this invention is an amide group containing monomer unit, an acid functional group containing unit.
  • a binder composition for a secondary battery which comprises a water-soluble polymer A containing a monomer unit and a monomer unit represented by the following general formula (1), and a binder composition for a secondary battery containing a solvent.
  • a method for producing a copolymer comprising copolymerizing an amide group-containing monomer, an acid functional group-containing monomer, and a monomer represented by the following general formula (3) to obtain a copolymer: A saponification step of saponifying the copolymer to obtain the polymer A.
  • R 1 represents a chemical single bond, a methylene group, an ethylene group, a 1,2-propylene group, or a 1,3-propylene group
  • R 2 and R 3 are each independently. And represents a hydrogen atom, a methyl group, an ethyl group, a propyl group, or an isopropyl group.
  • R 1 represents a chemical single bond, a methylene group, an ethylene group, a 1,2-propylene group or a 1,3-propylene group
  • R 4 represents a carbon number of 1 to 5 Represents the alkyl group of.
  • the manufacturing method of the functional layer for secondary batteries of this invention WHEREIN: For any of the above-mentioned secondary batteries on a base material. It is characterized by including a coating step of coating the slurry composition and a vacuum drying step of vacuum-drying the secondary battery slurry composition coated in the coating step. As described above, by using the method for producing a secondary battery functional layer including a coating step and a vacuum drying step, a secondary battery functional layer capable of producing a secondary battery having excellent cycle characteristics can be efficiently produced. it can.
  • vacuum drying means performing drying for removing a solvent such as water at a temperature of 80 kPa or lower and 40 ° C. or higher.
  • the binder composition for secondary batteries which can produce the secondary battery excellent in cycling characteristics can be provided. Further, according to the present invention, it is possible to provide a slurry composition for a secondary battery, which can produce a secondary battery having excellent cycle characteristics. Further, according to the present invention, it is possible to provide a functional layer for a secondary battery, which enables the production of a secondary battery having excellent cycle characteristics. In addition, according to the present invention, it is possible to provide an electrode layer for a secondary battery, which can produce a secondary battery having excellent cycle characteristics. Moreover, according to the present invention, a secondary battery having excellent cycle characteristics can be provided.
  • a binder composition for a secondary battery capable of producing a secondary battery having excellent cycle characteristics can be efficiently produced. Further, according to the present invention, it is possible to efficiently manufacture a secondary battery functional layer capable of manufacturing a secondary battery having excellent cycle characteristics.
  • the binder composition for a secondary battery of the present invention is, for example, an electrode layer formed on a current collector in an electrode, further above the electrode layer (that is, on an electrode base material) or a separator base material. It is used for forming the porous membrane layer formed on the above.
  • the slurry composition for a secondary battery of the present invention contains the binder composition for a secondary battery of the present invention, when preparing the functional layer for a secondary battery of the present invention or the electrode layer for a secondary battery of the present invention It is used as a material.
  • the functional layer for a secondary battery of the present invention is prepared using the slurry composition for a secondary battery of the present invention and constitutes, for example, a separator or a part of an electrode.
  • the electrode layer for a secondary battery of the present invention is prepared using the slurry composition for a secondary battery of the present invention, and constitutes a part of the electrode.
  • the secondary battery of the present invention includes the secondary battery functional layer of the present invention (electrode layer, adhesive layer, or porous membrane layer).
  • the binder composition for a secondary battery of the present invention contains polymer A and a solvent, and optionally polymer B, compound X, and other components.
  • the polymer A contains an amide group-containing monomer unit, an acid functional group-containing monomer unit, and a monomer unit represented by the general formula (1). Then, by using the binder composition for a secondary battery of the present invention, a secondary battery having excellent cycle characteristics can be manufactured.
  • the binder composition for a secondary battery of the present invention is a binder composition for a functional layer ( It can also be favorably used as a binder composition for an electrode layer, a binder composition for an adhesive layer, or a binder composition for a porous film layer).
  • the binder composition for a secondary battery of the present invention will be described by taking as an example the case where the binder composition for a secondary battery is used for forming a functional layer (electrode layer, adhesive layer, or porous film layer). .
  • Polymer A contains an amide group-containing monomer unit, an acid functional group-containing monomer unit, and a monomer unit represented by the general formula (1), and optionally an amide group-containing monomer.
  • a unit, a monomer unit containing an acid functional group, and a monomer unit other than the monomer unit represented by the general formula (1) may be contained.
  • the polymer A has such a monomer composition, it is possible to prepare a secondary battery slurry composition capable of producing a secondary battery having excellent cycle characteristics.
  • the polymer A is a water-soluble type. When the polymer A is water-soluble, the viscosity of the slurry composition can be controlled, and a functional layer (electrode layer, adhesive layer, or porous film layer) having a uniform film thickness can be obtained.
  • amide group-containing monomer unit examples include methacrylamide, acrylamide, dimethyl acrylamide, diethyl acrylamide, diacetone acrylamide, hydroxyethyl acrylamide, hydroxymethyl acrylamide, hydroxypropyl acrylamide, hydroxybutyl acrylamide. , And so on. These may be used individually by 1 type and may be used in combination of 2 or more types by arbitrary ratios. Of these, acrylamide is preferable from the viewpoint of the viscosity of the slurry composition.
  • the content of the amide group-containing monomer unit in the polymer A (the proportion of the amide group-containing monomer unit in all the monomer units contained in the polymer A) is 20% by mass or more. It is preferably 25% by mass or more, more preferably 35% by mass or more, particularly preferably 60% by mass or less, more preferably 55% by mass or less, 53 It is particularly preferable that the content is not more than mass%.
  • the acid functional group-containing monomer capable of forming the acid functional group-containing monomer unit may be a monomer having an acid functional group, for example, a monomer having a carboxylic acid group (carboxyl group). , A monomer having a sulfonic acid group, a monomer having a phosphoric acid group, and the like.
  • Examples of the monomer having a carboxylic acid group include monocarboxylic acid, dicarboxylic acid, and salts thereof (sodium salt, lithium salt, etc.).
  • Examples of the monocarboxylic acid include acrylic acid, methacrylic acid, and crotonic acid.
  • Examples of the dicarboxylic acid include maleic acid, fumaric acid, and itaconic acid.
  • Examples of the monomer having a sulfonic acid group include styrene sulfonic acid, vinyl sulfonic acid, methyl vinyl sulfonic acid, (meth) allyl sulfonic acid, ethyl (meth) acrylic acid-2-sulfonate, 2-acrylamido-2 -Methylpropanesulfonic acid, 3-allyloxy-2-hydroxypropanesulfonic acid, and salts thereof (lithium salt, sodium salt, etc.).
  • “(meth) allyl” means allyl and / or methallyl
  • “(meth) acryl” means acryl and / or methacryl.
  • Examples of the monomer having a phosphoric acid group include 2- (meth) acryloyloxyethyl phosphate, methyl-2- (meth) acryloyloxyethyl phosphate, ethyl- (meth) acryloyloxyethyl phosphate, and These salts (sodium salt, lithium salt, etc.) are mentioned.
  • “(meth) acryloyl” means acryloyl and / or methacryloyl.
  • the acid functional group-containing monomer one type may be used alone, or two or more types may be used in combination at an arbitrary ratio.
  • the acid functional group-containing monomer is preferably a monomer having a carboxylic acid group, more preferably methacrylic acid, itaconic acid, acrylic acid, maleic acid, from the viewpoint of copolymerizability in the polymer A. , Acrylic acid is more preferable.
  • the content of the acid functional group-containing monomer unit in the polymer A (the ratio of the acid functional group-containing monomer unit in all the monomer units contained in the polymer A) is 10% by mass or more. Is preferred, 15% by mass or more is more preferred, 18% by mass or more is particularly preferred, 45% by mass or less is preferred, and 40% by mass or less is more preferred. , 35 mass% or less is particularly preferable.
  • Examples of the monomer capable of forming the monomer unit represented by the general formula (1) include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl valerate, vinyl isovalerate, and hexanoic acid.
  • Examples include monomers represented by the following general formula (3) such as vinyl. These may be used individually by 1 type and may be used in combination of 2 or more types by arbitrary ratios. Among these, vinyl acetate, vinyl propionate, vinyl butyrate, and vinyl isobutyrate are preferable from the viewpoint of saponification, and vinyl acetate and vinyl propionate are more preferable.
  • R 1 represents a chemical single bond, a methylene group, an ethylene group, a 1,2-propylene group or a 1,3-propylene group
  • R 4 represents a carbon number of 1 to 5 Represents the alkyl group of.
  • R 1 may be any of a chemical single bond, a methylene group, an ethylene group, a 1,2-propylene group, and a 1,3-propylene group, and is obtained by crosslinking the copolymers described below.
  • a chemical single bond is preferable because the degree of freedom of the crosslinked body is small.
  • alkyl group having 1 to 5 carbon atoms for R 4 include, for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group, tert-butyl group, n —Pentyl group, isopentyl group, neopentyl group, sec-pentyl group, tert-pentyl group.
  • a methyl group, an ethyl group, a propyl group and an isopropyl group are preferable, and a methyl group and an ethyl group are more preferable.
  • the content of the monomer unit represented by the general formula (1) in the polymer A (the unit represented by the general formula (1) in all the monomer units contained in the polymer A is The proportion of the monomer unit) is preferably 5% by mass or more, more preferably 20% by mass or more, particularly preferably 25% by mass or more, and preferably 40% by mass or less, It is more preferably 35% by mass or less.
  • the content of the monomer unit represented by the general formula (1) in the polymer A is not more than the above upper limit, defects on the coated surface are reduced, and the binder composition is used.
  • the cycle characteristics of the secondary battery including the electrode or the separator formed as described above can be further improved.
  • the monomer unit other than the amide group-containing monomer unit, the acid functional group-containing monomer unit and the monomer unit represented by the general formula (1) is not particularly limited, and examples thereof include carboxylic acid ester monomer units. Examples thereof include a monomer unit, an aromatic monomer unit, and an aliphatic conjugated diene monomer unit.
  • the other monomer units may be used alone or in combination of two or more kinds at any ratio.
  • the content of the other monomer units in the polymer A (ratio of the other monomer units in all the monomer units contained in the polymer A) is 0% by mass or more and 10 It is preferably not more than mass%.
  • Carboxylic acid ester monomer unit examples of the carboxylic acid ester monomer capable of forming the carboxylic acid ester monomer unit include hydroxymethyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxymethyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate and hydroxybutyl.
  • Methacrylate methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) Acrylate, 2-ethylhexyl (meth) acrylate, nonanyl (meth) acrylate, allyl (meth) acrylate, etc. It is. These may be used individually by 1 type and may be used in combination of 2 or more types by arbitrary ratios.
  • hydroxyethyl acrylate is preferable from the viewpoint of polymerization stability and thermal crosslinkability during electrode vacuum drying.
  • (meth) acrylate means an acrylate and / methacrylate.
  • the aromatic monomer capable of forming an aromatic monomer unit and the aliphatic conjugated diene monomer capable of forming an aliphatic conjugated diene monomer unit will be described later in the section "Polymer B". It is possible to use the same one as that.
  • the polymer A is produced by polymerizing a monomer composition containing the above-mentioned monomer in an aqueous solvent such as water to obtain a copolymer, and saponifying the obtained copolymer. You can At this time, the content ratio of each monomer in the monomer composition can be determined according to the content (content ratio) of each repeating unit (monomer unit) in the polymer A.
  • the polymerization mode is not particularly limited, and any method such as a solution polymerization method, a suspension polymerization method, a bulk polymerization method and an emulsion polymerization method can be used.
  • any reaction such as ionic polymerization, radical polymerization and living radical polymerization can be used.
  • the additives such as an emulsifier, a dispersant, a polymerization initiator and a polymerization aid used for the polymerization, those generally used can be used.
  • the amount of these additives used may be a commonly used amount.
  • the polymerization conditions can be appropriately adjusted depending on the polymerization method and the type of polymerization initiator.
  • the reagent used for the saponification alkali treatment is preferably lithium hydroxide, sodium hydroxide or potassium hydroxide, and more preferably lithium hydroxide.
  • the reaction temperature in the alkali treatment for saponification is preferably 70 ° C or higher, more preferably 80 ° C or higher, particularly preferably 90 ° C or higher, preferably 100 ° C or lower, and 98 ° C or lower. Is more preferable, and it is particularly preferable that the temperature is 96 ° C. or lower.
  • the reaction time in the alkali treatment for saponification is preferably 5 minutes or longer, more preferably 10 minutes or longer, particularly preferably 15 minutes or longer, more preferably 360 minutes or shorter, and 300 minutes or shorter. Is more preferable and 240 minutes or less is particularly preferable.
  • the target degree of saponification can be achieved by setting the reaction time in the alkali treatment of saponification to the above lower limit or more. On the other hand, by setting the reaction time in the alkali treatment for saponification to the above upper limit value or less, it is possible to prevent the molecular chain from breaking.
  • the degree of saponification is preferably 50 mol% or more, more preferably 90 mol% or more, and particularly preferably 98 mol% or more. By setting the degree of saponification to be the above lower limit or more, cycle characteristics can be improved.
  • dehydration condensation between the hydroxyl groups in the saponified copolymer gives a cross-linking part structure of "-R 1 -O-R 1- ".
  • the two R 1 's in “-R 1 -O-R 1- " may be the same or different.
  • the hydroxyl groups in the saponified copolymer are dehydrated and condensed to cross-link the copolymers, and, for example, the conductivity based on the volume expansion of the silicon-based negative electrode active material as the metal-based negative electrode active material described later is obtained. It is possible to prevent the deterioration of the performance of the secondary battery due to the disconnection of the path.
  • the crosslinked portion structure (-R 1 -OR 1- ) of the saponified copolymer is at most 6 (the maximum number of carbon atoms in R 1 is 3), the crosslinked portion structure (- The length of R 1 —O—R 1 —) is relatively short, and the degree of freedom of the molecular chain of the copolymer is small.
  • the dehydration condensation of the hydroxyl groups in the saponified copolymer is performed by vacuum drying the slurry composition and / or vacuum drying after forming the electrode layer.
  • the conditions for vacuum drying are, for example, a drying temperature of 50 ° C. or higher and 200 ° C. or lower, and a drying time of 360 minutes or longer and 1200 minutes or shorter.
  • the weight average molecular weight of the polymer A is preferably 1,000,000 or more, more preferably 2,000,000 or more, particularly preferably 5,000,000 or more, and preferably 10,000,000 or less, 800 It is more preferably 10,000 or less, and particularly preferably 7 million or less.
  • the weight average molecular weight of the polymer A is preferably 1,000,000 or more, more preferably 2,000,000 or more, particularly preferably 5,000,000 or more, and preferably 10,000,000 or less, 800 It is more preferably 10,000 or less, and particularly preferably 7 million or less.
  • the electrolyte solution swelling degree of the polymer A is preferably 100% by mass or more, more preferably 150% by mass or less, more preferably 145% by mass or less, and 135% by mass or less. Is particularly preferable. By setting the electrolytic solution swelling degree of the polymer A to be equal to or less than the above upper limit value, the cycle characteristics of the obtained secondary battery can be further improved.
  • the polymer B contains at least one of an aliphatic conjugated diene monomer unit and an aromatic monomer unit, and preferably contains both an aliphatic conjugated diene monomer unit and an aromatic monomer unit.
  • the polymer B may optionally contain a monomer unit other than the aliphatic conjugated diene monomer unit and the aromatic monomer unit.
  • the polymer B is not a water-soluble type but an aqueous dispersion type.
  • the aliphatic conjugated diene monomer capable of forming the aliphatic conjugated diene monomer unit is not particularly limited, and 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2, Examples thereof include 3-dimethyl-1,3-butadiene. Among these, 1,3-butadiene and isoprene are preferable as the aliphatic conjugated diene monomer, and 1,3-butadiene is more preferable from the viewpoint of crosslinking density and distance between crosslinking points.
  • the aliphatic conjugated diene monomer may be used alone or in combination of two or more kinds at an arbitrary ratio.
  • the content of the aliphatic conjugated diene monomer unit in the polymer B (the ratio of the aliphatic conjugated diene monomer unit in all the monomer units contained in the polymer B) is 10% by mass or more. Is preferable, 15% by mass or more is more preferable, 20% by mass or more is particularly preferable, 90% by mass or less is preferable, and 85% by mass or less is more preferable. Is particularly preferably 80% by mass or less.
  • the aromatic monomer capable of forming the aromatic monomer unit is not particularly limited, and aromatic vinyl such as styrene, styrenesulfonic acid and its salts, ⁇ -methylstyrene, butoxystyrene, vinylnaphthalene, etc. Examples thereof include monomers. Of these, styrene is preferable as the aromatic monomer from the viewpoint of the adhesive strength of the functional layer and the electrode layer.
  • the aromatic monomers may be used alone or in combination of two or more at an arbitrary ratio.
  • the content of the aromatic monomer unit in the polymer B (the ratio of the aromatic monomer unit in all the monomer units contained in the polymer B) is 10% by mass or more. It is preferably 15% by mass or more, particularly preferably 20% by mass or more, preferably 90% by mass or less, more preferably 85% by mass or less, and 80% by mass. The following is particularly preferable.
  • the content of the aromatic monomer unit in the polymer B is at least the above lower limit value, deterioration of electrode swelling can be suppressed and deterioration of cycle characteristics can be suppressed.
  • the flexibility of the electrode can be improved, brittle fracture can be suppressed, and the peel strength can be improved.
  • the monomer unit other than the aliphatic conjugated diene monomer unit and the aromatic monomer unit is not particularly limited, and examples thereof include a carboxylic acid ester monomer unit and a carboxylic acid group-containing monomer unit. ..
  • the other monomer units may be used alone or in combination of two or more kinds at any ratio.
  • the content of the other monomer units in the polymer B (the ratio of the other monomer units in all the monomer units contained in the polymer B) is 0% by mass or more, and 7 It is preferably not more than mass%.
  • Carboxylic acid ester monomer unit examples of the carboxylic acid ester monomer capable of forming the carboxylic acid ester monomer unit include hydroxymethyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxymethyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate and hydroxybutyl.
  • Methacrylate methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) Acrylate, 2-ethylhexyl (meth) acrylate, nonanyl (meth) acrylate, allyl (meth) acrylate, etc. It is. These may be used individually by 1 type and may be used in combination of 2 or more types by arbitrary ratios. Among these, methyl (meth) acrylate, butyl (meth) acrylate, hydroxyethyl acrylate, and allyl (meth) acrylate are preferable from the viewpoint of polymerization stability.
  • Carboxylic acid group-containing monomer unit examples of the carboxylic acid group-containing monomer capable of forming the carboxylic acid group-containing monomer unit include methacrylic acid, acrylic acid, maleic acid, and itaconic acid. These may be used individually by 1 type and may be used in combination of 2 or more types by arbitrary ratios. Among these, methacrylic acid is preferable from the viewpoint of polymerization stability.
  • the compound X is a compound represented by the following general formula (2).
  • Examples of the compound X include acetic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, hexanoic acid, lithium acetate, sodium acetate, potassium acetate, lithium butyrate, sodium butyrate, potassium butyrate, lithium isobutyrate, and sodium isobutyrate.
  • lithium acetate is preferable from the viewpoints of saponification efficiency and obtained secondary battery characteristics.
  • X represents a hydrogen atom or an alkali metal atom
  • R 4 has the same meaning as described above, and its preferred examples are also the same as those described above.
  • the alkali metal atom of X is preferably lithium, sodium or potassium, and more preferably lithium, from the viewpoint of saponification efficiency and secondary battery characteristics obtained.
  • the content ratio of the compound X with respect to the solid content of the polymer A is preferably 100 mass ppm or more, more preferably 200 mass ppm or more, particularly preferably 300 mass ppm or more, and 500000 mass ppm or less. Is preferable and 3000 mass ppm or less is more preferable.
  • the content ratio of the compound X is set to be the above lower limit value or more, it is possible to suppress the viscosity of the slurry composition for a secondary battery from increasing.
  • the content ratio of the compound X to be equal to or less than the above upper limit value, it is possible to suppress precipitation of lithium metal.
  • the method of incorporating the compound X into the binder composition for a secondary battery is not particularly limited.
  • the method using saponification described above is employed to generate the compound X which is a carboxylic acid (and / or a salt thereof) together with the polymer A, and the polymer A and the compound X are then formed.
  • a binder composition containing can be prepared.
  • the solvent contained in the binder composition for a secondary battery of the present invention is not particularly limited and may be water.
  • the solvent may be an aqueous solution or a mixed solution of water and a small amount of organic solvent.
  • the binder composition for a secondary battery of the present invention may contain components such as a preservative, a reinforcing material, a leveling agent, a viscosity modifier, and an electrolyte solution additive, in addition to the above components. These are not particularly limited as long as they do not affect the battery reaction, and known ones such as those described in International Publication No. 2012/115096 can be used. Moreover, these components may be used individually by 1 type, and may be used in combination of 2 or more types in arbitrary ratios.
  • the method for preparing the binder composition for a secondary battery of the present invention is not particularly limited, but for example, the preparation of polymer A, which is a water-soluble polymer (water-soluble polymer), is carried out in an aqueous medium, When the polymer A is obtained as an aqueous solution, the aqueous solution of the polymer A may be used as it is as the binder composition for a secondary battery, or the polymer B and / or other components may be added to the aqueous solution of the polymer A. It may be a binder composition for a secondary battery.
  • the method for producing a binder composition for a secondary battery of the present invention is a method for producing the binder composition for a secondary battery of the present invention described above, which includes at least a copolymerization step and a saponification step, and is required. And optionally other steps.
  • the copolymerization step is a step of copolymerizing the amide group-containing monomer, the acid functional group-containing monomer, and the monomer represented by the general formula (3) to obtain a copolymer.
  • the saponification step is a step of saponifying the copolymer to obtain the polymer A.
  • the conditions of copolymerization and saponification are as described above in the section "Method for preparing polymer A". Examples of the other steps include a step of adding a preservative and a step of adjusting the solid content concentration.
  • the secondary battery slurry composition of the present invention includes at least the secondary battery binder composition of the present invention, further contains non-conductive fine particles or electrode active material, any other component, water, etc. It is a slurry composition used as a dispersion medium.
  • the functional layer obtained by using the secondary battery slurry composition of the present invention is good as a porous film layer having excellent heat resistance and strength. Can function to.
  • the functional layer obtained by using the secondary battery slurry composition of the present invention has excellent peel strength and uses electrodes.
  • the secondary battery can function well as an electrode layer capable of exhibiting excellent cycle characteristics.
  • the ratio of the mass of the polymer A to the mass of the total solid content of the slurry composition containing the electrode active material is 1.0 mass%. It is preferably at least 2.0 mass%, more preferably at least 2.0 mass%, preferably at most 7.0 mass%, more preferably at most 5.0 mass%.
  • the ratio By setting the ratio to the above lower limit or more, it is possible to suppress deterioration of the dispersibility of the electrode active material in the case where the slurry composition contains the electrode active material, and to reduce the cycle characteristics of the obtained secondary battery. Can be suppressed.
  • the ratio By setting the ratio to be equal to or less than the upper limit value, it is possible to suppress a decrease in cell capacity and an increase in cell resistance of the obtained secondary battery.
  • ⁇ Ratio of mass of polymer B to mass of total solid content of slurry composition containing electrode active material mass of polymer B containing electrode active material / mass of total solid content of slurry composition
  • 0.2 mass% It is preferably at least 0.5% by mass, more preferably at least 0.5% by mass, and preferably at most 3.0% by mass, more preferably at most 2.0% by mass.
  • the adhesive strength of the obtained electrode layer can be improved, and by extension, the peel strength of the electrode can be improved.
  • the above ratio is set to be equal to or less than the above upper limit, it is possible to prevent a decrease in cell capacity and an increase in cell resistance of the obtained secondary battery.
  • the ratio of the mass of the polymer A to the total solid mass of the slurry composition containing the non-conductive fine particles is 0.2. It is preferably at least mass%, more preferably at least 0.5 mass%, at most 7.0 mass%, and even more preferably at most 4.0 mass%.
  • ⁇ Ratio of mass of polymer B to mass of total solid content of slurry composition containing non-conductive fine particles mass of polymer B / mass of total solid content of slurry composition containing non-conductive fine particles
  • the ratio of the mass of the polymer B to the mass of the total solid content of the slurry composition containing the non-conductive fine particles is 0.2. It is preferably at least mass%, more preferably at least 0.5 mass%, preferably at most 7.0 mass%, more preferably at most 5.0 mass%.
  • the non-conductive fine particles are particles that do not dissolve in a dispersion medium such as water and the non-aqueous electrolyte solution of the secondary battery, and the shape thereof is maintained even in them. Since the non-conductive fine particles are electrochemically stable, they are stably present in the functional layer under the usage environment of the secondary battery.
  • the non-conductive fine particles for example, various kinds of inorganic fine particles and organic fine particles can be used.
  • the non-conductive fine particles both inorganic fine particles and organic fine particles can be used, but the inorganic fine particles are usually used.
  • the material of the non-conductive fine particles is preferably a material that stably exists in the usage environment of the secondary battery and is electrochemically stable. From this point of view, preferred examples of the material of the non-conductive fine particles include aluminum oxide (alumina), hydrated aluminum oxide (boehmite), silicon oxide, magnesium oxide (magnesia), calcium oxide, titanium oxide (titania).
  • oxide particles such as alumina-silica composite oxide
  • nitride particles such as aluminum nitride and boron nitride
  • covalent bond crystal particles such as silicon and diamond
  • barium sulfate, calcium fluoride, barium fluoride And the like, and slightly soluble ionic crystal particles such as talc and clay fine particles such as talc and montmorillonite. Further, these particles may be subjected to element substitution, surface treatment, solid solution treatment or the like, if necessary.
  • the above non-conductive fine particles may be used alone or in combination of two or more.
  • Aluminum oxide (alumina) is preferable as the non-conductive fine particles.
  • the particle size of the non-conductive fine particles is not particularly limited and may be the same as the conventionally used non-conductive fine particles.
  • the mass ratio of the non-conductive fine particles to the total solid mass of the slurry composition is preferably 85% by mass or more, and 87% by mass More preferably, it is more preferably 99% by mass or less, and more preferably 97% by mass or less.
  • Good heat resistance can be obtained by setting the above ratio to the above lower limit or more. On the other hand, by setting the above ratio to the above upper limit or less, good adhesion strength can be imparted to the porous film.
  • the electrode active material is a material that transfers electrons at the electrodes (positive electrode, negative electrode) of the secondary battery. Then, for example, as an electrode active material (positive electrode active material, negative electrode active material) of a lithium ion secondary battery, a material capable of inserting and extracting lithium is usually used.
  • Cathode active material Specifically, a compound containing a transition metal, such as a transition metal oxide, a transition metal sulfide, or a composite metal oxide of lithium and a transition metal, can be used as the positive electrode active material.
  • transition metals include Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Mo, and the like.
  • examples of the transition metal oxide include MnO, MnO 2 , V 2 O 5 , V 6 O 13 , TiO 2 , Cu 2 V 2 O 3 , amorphous V 2 O-P 2 O 5 , and amorphous. Quality MoO 3 , amorphous V 2 O 5 , amorphous V 6 O 13 and the like.
  • transition metal sulfides include TiS 2 , TiS 3 , amorphous MoS 2 , and FeS.
  • Examples of the composite metal oxide of lithium and a transition metal include a lithium-containing composite metal oxide having a layered structure, a lithium-containing composite metal oxide having a spinel structure, and a lithium-containing composite metal oxide having an olivine structure. Be done.
  • lithium-containing composite metal oxide having a layered structure examples include lithium-containing cobalt oxide (LiCoO 2 ), lithium-containing nickel oxide (LiNiO 2 ), and Co—Ni—Mn lithium-containing composite oxide (Li (CoMnNi ) O 2 ), a lithium-containing composite oxide of Ni—Mn—Al, a lithium-containing composite oxide of Ni—Co—Al, a solid solution of LiMaO 2 and Li 2 MbO 3, and the like.
  • lithium-containing composite oxide of Co—Ni—Mn include Li [Ni 0.5 Co 0.2 Mn 0.3 ] O 2 and Li [Ni 1/3 Co 1/3 Mn 1/3 ] O 2 .
  • Examples of the solid solution of LiMaO 2 and Li 2 MbO 3 include xLiMaO 2 ⁇ (1-x) Li 2 MbO 3 .
  • x represents a number satisfying 0 ⁇ x ⁇ 1
  • Ma represents one or more kinds of transition metals having an average oxidation state of 3+
  • Mb represents one or more kinds of transition metals having an average oxidation state of 4+.
  • Represent Examples of such solid solution include Li [Ni 0.17 Li 0.2 Co 0.07 Mn 0.56 ] O 2 .
  • the “average oxidation state” refers to the average oxidation state of the “one or more kinds of transition metals” and is calculated from the molar amount of transition metal and the valence.
  • lithium-containing mixed metal oxide having a spinel structure examples include lithium manganate (LiMn 2 O 4 ) and compounds obtained by substituting a part of Mn of lithium manganate (LiMn 2 O 4 ) with another transition metal.
  • Specific examples include Li s [Mn 2-t Mc t] O 4 , such as LiNi 0.5 Mn 1.5 O 4.
  • Mc represents one or more kinds of transition metals having an average oxidation state of 4+.
  • Mc include Ni, Co, Fe, Cu, Cr and the like.
  • t represents a number satisfying 0 ⁇ t ⁇ 1
  • s represents a number satisfying 0 ⁇ s ⁇ 1.
  • a lithium-excess spinel compound represented by Li 1 + x Mn 2-x O 4 (0 ⁇ X ⁇ 2) can also be used.
  • Examples of the lithium-containing composite metal oxide having an olivine type structure include olivine type phosphorus represented by Li y MdPO 4 such as olivine type lithium iron phosphate (LiFePO 4 ) and olivine type lithium manganese phosphate (LiMnPO 4 ). Examples thereof include lithium acid compounds.
  • Md represents one or more kinds of transition metals having an average oxidation state of 3+, and examples thereof include Mn, Fe, and Co.
  • y represents a number satisfying 0 ⁇ y ⁇ 2.
  • Md may be partially substituted with another metal.
  • Examples of the replaceable metal include Cu, Mg, Zn, V, Ca, Sr, Ba, Ti, Al, Si, B and Mo.
  • examples of the negative electrode active material include a carbon-based negative electrode active material, a metal-based negative electrode active material, and a negative electrode active material combining these.
  • the carbon-based negative electrode active material refers to an active material having lithium as a main skeleton, into which lithium can be inserted (also referred to as “dope”).
  • examples of the carbon-based negative electrode active material include a carbonaceous material and graphite. Quality materials.
  • the carbonaceous material is a material having a low degree of graphitization (that is, low crystallinity) obtained by heat-treating a carbon precursor at 2000 ° C. or lower to carbonize it.
  • the lower limit of the heat treatment temperature for carbonization is not particularly limited, but may be 500 ° C. or higher, for example.
  • Examples of the carbonaceous material include graphitizable carbon that easily changes the carbon structure depending on the heat treatment temperature and non-graphitizable carbon having a structure close to an amorphous structure represented by glassy carbon.
  • examples of the graphitizable carbon include a carbon material obtained from tar pitch obtained from petroleum or coal as a raw material.
  • non-graphitizable carbon examples include a fired phenol resin, a polyacrylonitrile-based carbon fiber, pseudo isotropic carbon, a furfuryl alcohol resin fired body (PFA), and hard carbon.
  • the graphitic material is a material having high crystallinity close to that of graphite, which is obtained by heat-treating graphitizable carbon at 2000 ° C. or higher.
  • the upper limit of the heat treatment temperature is not particularly limited, but may be 5000 ° C. or lower, for example.
  • Examples of the graphite material include natural graphite and artificial graphite.
  • the artificial graphite for example, artificial graphite obtained by heat-treating carbon containing easily graphitizable carbon at 2800 ° C. or higher, graphitized MCMB obtained by heat-treating MCMB at 2000 ° C. or higher, and mesophase pitch-based carbon fiber at 2000 ° C.
  • Examples include the graphitized mesophase pitch-based carbon fiber heat-treated as described above.
  • the metal-based negative electrode active material is an active material containing a metal, and usually has a structure containing an element capable of inserting lithium, and has a theoretical electric capacity per unit mass of 500 mAh / when lithium is inserted.
  • the metal-based active material include lithium metal and elemental metals capable of forming a lithium alloy (for example, Ag, Al, Ba, Bi, Cu, Ga, Ge, In, Ni, P, Pb, Sb, Si, Sn). , Sr, Zn, Ti, etc.) and alloys thereof, and their oxides, sulfides, nitrides, silicides, carbides, phosphides and the like.
  • an active material containing silicon silicon-based negative electrode active material
  • the lithium-ion secondary battery can have a high capacity by using the silicon-based negative electrode active material.
  • silicon-based negative electrode active material for example, silicon (Si), an alloy containing silicon, SiO, SiO x , a compound of Si-containing material and conductive carbon obtained by coating or compounding Si-containing material with conductive carbon. And so on. Note that these silicon-based negative electrode active materials may be used alone or in combination of two or more.
  • the alloy containing silicon examples include an alloy composition containing silicon, aluminum, a transition metal such as iron, and a rare earth element such as tin and yttrium.
  • SiO x is a compound containing at least one of SiO and SiO 2 and Si, and x is usually 0.01 or more and less than 2. Then, SiO x can be formed by utilizing, for example, a disproportionation reaction of silicon monoxide (SiO). Specifically, SiO x can be prepared by heat treating SiO, optionally in the presence of a polymer such as polyvinyl alcohol, to produce silicon and silicon dioxide. The heat treatment can be carried out at a temperature of 900 ° C. or higher, preferably 1000 ° C. or higher in an atmosphere containing organic gas and / or vapor after pulverizing and mixing SiO and optionally a polymer.
  • SiO x is a compound containing at least one of SiO and SiO 2 and Si, and x is usually 0.01 or more and less than 2.
  • SiO x can be formed by utilizing, for example, a disproportionation reaction of silicon monoxide (SiO).
  • SiO x can be prepared by heat treating
  • the composite of the Si-containing material and conductive carbon for example, a pulverized mixture of SiO, a polymer such as polyvinyl alcohol, and optionally a carbon material is heat-treated under an atmosphere containing, for example, an organic gas and / or steam.
  • the compound can be mentioned.
  • the composite compound is a method of coating the surface of SiO particles by a chemical vapor deposition method using an organic gas, a composite particle of SiO particles and graphite or artificial graphite by a mechanochemical method (granulation). It can also be obtained by a known method such as
  • the ratio of the mass of the carbon-based negative electrode active material to the mass of the total solid content of the slurry composition is preferably 50 mass% or more, 60 It is more preferably at least mass%, preferably at most 90 mass%, more preferably at most 85 mass%.
  • the above ratio By setting the above ratio to the above lower limit or more, it is possible to suppress a decrease in the buffering effect of the metal-based negative electrode active material (silicon-based active material) of the carbon-based negative electrode active material (graphite), and to suppress a decrease in cell capacity. can do. On the other hand, by setting the above ratio to the above upper limit value or less, the cycle characteristics of the obtained secondary battery can be improved.
  • the ratio of the mass of the metal-based negative electrode active material to the mass of the total solid content of the slurry composition is preferably 5 mass% or more. It is more preferably at least mass%, preferably at most 40 mass%, more preferably at most 30 mass%.
  • the slurry composition for a secondary battery may contain any other component in addition to the components described above.
  • the optional component is not particularly limited as long as it does not unduly affect the battery reaction in the secondary battery using the functional layer (porous film layer, adhesive layer, or electrode layer).
  • the type of the arbitrary component may be one type or two or more types.
  • the optional component include a particulate binder (excluding those corresponding to the polymer B), a wetting agent, a leveling agent, an electrolytic solution decomposition inhibitor, and the like.
  • the above-described secondary battery slurry composition can be prepared, for example, by dispersing the above components in an aqueous medium as a dispersion medium. Specifically, a ball mill, a sand mill, a bead mill, a pigment disperser, a crusher, an ultrasonic disperser, a homogenizer, a planetary mixer, and a mix of the above-mentioned components and an aqueous medium using a mixer such as fill mix.
  • a mixer such as fill mix.
  • a high dispersion device such as a bead mill, a roll mill or a fill mix may be used.
  • the above components and the aqueous medium can be mixed generally at room temperature to 80 ° C. for 10 minutes to several hours.
  • water is usually used as the aqueous medium, but an aqueous solution of an arbitrary compound, a mixed solution of a small amount of an organic medium and water, or the like may be used.
  • the water used as an aqueous medium The water that the binder composition contained may also be included.
  • the functional layer for a secondary battery of the present invention is preferably formed from a slurry composition for a secondary battery containing the non-conductive fine particles described above or the electrode active material described above, and for example, for the secondary battery described above. It can be formed by applying the slurry composition to the surface of a suitable substrate to form a coating film, and then drying the formed coating film. That is, the functional layer for a secondary battery of the present invention is composed of a dried product of the above-described slurry composition for a secondary battery, and is usually the polymer A, the non-conductive fine particles or the electrode active material, and optionally It contains the polymer B, the compound X, and / or the other components.
  • the abundance ratio of each component (excluding a dispersion medium such as water) contained in the secondary battery functional layer of the present invention is usually the abundance ratio of each component contained in the above-described secondary battery slurry composition.
  • the preferable abundance ratio of each component in the secondary battery functional layer is the same as the preferable abundance ratio of each component in the above-described secondary battery slurry composition.
  • the functional layer for a secondary battery of the present invention is formed from the slurry composition for a secondary battery of the present invention, it also functions well as a porous membrane layer or an electrode layer having excellent heat resistance and strength.
  • the functional layer for secondary batteries of the present invention can improve battery characteristics such as cycle characteristics of the secondary battery.
  • the base material forming the secondary battery functional layer is not particularly limited, and for example, when the secondary battery functional layer is used as a member forming a part of the separator, the base material is a separator base material.
  • a functional layer when a functional layer is used as a member forming a part of an electrode, a current collector may be used as a base material, and an electrode layer is formed on the current collector. You may use an electrode base material.
  • the usage of the functional layer formed on the base material is not particularly limited, and for example, the functional layer (porous membrane layer) may be formed on the separator base material or the like and used as it is as a battery member such as a separator.
  • the functional layer may be formed on the current collector and used as the electrode, or the functional layer (porous membrane layer) may be formed on the electrode base material and used as the electrode.
  • the functional layer formed on the release base material may be once peeled from the base material and attached to another base material to be used as a battery member.
  • the separator substrate is not particularly limited, and examples thereof include known separator substrates such as organic separator substrates.
  • the organic separator base material is a porous member made of an organic material, and examples of the organic separator base material include polyethylene, polyolefin resins such as polypropylene, and microporous membranes containing an aromatic polyamide resin, and the like.
  • a microporous membrane made of polyethylene is preferable because it is excellent.
  • the thickness of the organic separator substrate can be any thickness, and is usually 0.5 ⁇ m or more, preferably 5 ⁇ m or more, and is usually 40 ⁇ m or less, preferably 30 ⁇ m or less, more preferably 20 ⁇ m or less.
  • the current collector is not particularly limited, and a known current collector can be used. Examples of such a known current collector include those described later in the section of "electrode layer for secondary battery".
  • the electrode base material (positive electrode base material and negative electrode base material) is not particularly limited, and examples thereof include an electrode base material having an electrode layer formed on a current collector.
  • a current collector an electrode active material in the electrode layer (positive electrode active material, negative electrode active material) and an electrode layer binder (positive electrode composite material layer binder, negative electrode composite material layer binder),
  • a known method can be used for forming the electrode layer on the current collector, and examples thereof include those described in JP-A-2013-145763.
  • the polymer A contained in the binder composition for a secondary battery of the present invention may be used as the binder for the electrode layer.
  • the release base material for forming the functional layer is not particularly limited, and a known release base material can be used.
  • Examples of the method for forming a functional layer on a substrate such as the separator substrate, the current collector, and the electrode substrate described above include the following methods. 1) A method of applying the slurry composition for a secondary battery to the surface of a separator substrate, a current collector or an electrode substrate, and then drying. 2) A method of immersing the separator base material, the current collector or the electrode base material in the slurry composition for a secondary battery, and then drying it. 3) The functional composition for secondary batteries is manufactured by applying the slurry composition for secondary batteries on a release base material and drying it, and using the obtained functional layer for secondary batteries as a separator base material, a collector or an electrode base material.
  • the method 1) is particularly preferable because it is easy to control the film thickness of the secondary battery functional layer.
  • the method 1) is specifically a step (application step) of applying the slurry composition for a secondary battery onto a base material (separator base material, current collector or electrode base material), base material (separator base material). , A current collector or an electrode base material) is dried to form a functional layer (functional layer forming step).
  • the method of coating the secondary battery slurry composition on the substrate is not particularly limited, for example, doctor blade method, reverse roll method, direct roll method, gravure method, extrusion method, brush coating method. And the like.
  • a known method can be used without particular limitation, for example, hot air, hot air, drying with low humidity air, Examples thereof include vacuum drying and a drying method by irradiation with infrared rays or electron beams.
  • the drying conditions are not particularly limited, but the drying temperature is preferably 50 to 100 ° C., and the drying time is preferably 5 to 30 minutes.
  • the thickness of the secondary battery functional layer formed on the base material can be appropriately adjusted.
  • Method for manufacturing functional layer for secondary battery is a method of manufacturing the functional layer for secondary batteries of this invention, Comprising: A coating process and a vacuum drying process are included.
  • the coating step is a step of coating the above-described secondary battery slurry composition of the present invention on a substrate.
  • the method of coating the secondary battery slurry composition on the substrate is not particularly limited, for example, doctor blade method, reverse roll method, direct roll method, gravure method, extrusion method, brush coating method. And the like.
  • the vacuum drying step is a step of vacuum-drying the secondary battery slurry composition applied in the applying step.
  • vacuum-drying a secondary battery slurry composition refers to a series of processes for producing a functional layer by removing a dispersion medium (solvent) from a liquid secondary battery slurry composition. This means performing vacuum drying, and most of the solvent of the slurry composition is removed to obtain a dried product, and vacuum drying in a state where a functional layer is substantially formed is also included. And the said vacuum drying may be performed after incorporating the battery member provided with the dried material of the slurry composition into the secondary battery.
  • the conditions for vacuum drying are, for example, a drying temperature of 50 ° C. or higher and 200 ° C. or lower, and a drying time of 360 minutes or longer and 1200 minutes or shorter. By vacuum drying, dehydration condensation of the hydroxyl groups in the saponified copolymer described above can be performed.
  • the electrode layer for a secondary battery of the present invention is formed from a slurry composition for a secondary battery containing the above-mentioned electrode active material, and for example, a suitable current collector for the slurry composition for a secondary battery described above. It can be formed by applying the coating to the surface of to form a coating film and then drying the formed coating film. That is, the electrode layer for a secondary battery of the present invention is a dried product of the slurry composition for a secondary battery described above, and is usually the polymer A, the electrode active material, and the optional polymer B, It contains the above-mentioned optional compound X and optionally the above-mentioned other components.
  • the secondary battery electrode layer is included in the secondary battery functional layer (in other words, the secondary battery electrode layer is an example of the secondary battery functional layer).
  • the abundance ratio of each component (excluding a dispersion medium such as water) contained in the secondary battery electrode layer of the present invention is usually the abundance ratio of each component contained in the above-described secondary battery slurry composition.
  • the preferable abundance ratio of each component in the secondary battery electrode layer is the same as the preferable abundance ratio of each component in the above-described secondary battery slurry composition. Since the secondary battery electrode layer of the present invention is formed from the secondary battery slurry composition of the present invention, it has high peel strength, and makes the secondary battery exhibit excellent cycle characteristics. be able to.
  • the secondary battery electrode layer of the present invention includes, for example, a step of applying the above-described secondary battery slurry composition on a current collector (application step) and a secondary battery applied on the current collector.
  • the slurry composition is dried to form an electrode layer on the current collector (drying step).
  • the method for applying the slurry composition for a secondary battery on the current collector is not particularly limited, and a known method can be used. Specifically, as a coating method, a doctor blade method, a dipping method, a reverse roll method, a direct roll method, a gravure method, an extrusion method, a brush coating method or the like can be used. At this time, the slurry composition may be applied to only one surface of the current collector or both surfaces thereof. The thickness of the slurry film on the current collector after coating and before drying can be appropriately set according to the thickness of the electrode layer obtained by drying.
  • a current collector for applying the secondary battery slurry composition a material having electrical conductivity and electrochemical durability is used.
  • a current collector for example, a current collector made of iron, copper, aluminum, nickel, stainless steel, titanium, tantalum, gold, platinum, or the like can be used.
  • copper foil is particularly preferable as the current collector used for the negative electrode.
  • An aluminum foil is particularly preferable as the current collector used for the positive electrode.
  • the said material may be used individually by 1 type and may be used in combination of 2 or more types by arbitrary ratios.
  • the method for drying the secondary battery slurry composition on the current collector is not particularly limited and known methods can be used, for example, hot air, hot air, low-humid air drying, vacuum drying, infrared rays or electron beams. And a drying method by irradiation.
  • a drying method by irradiation By thus drying the secondary battery slurry composition on the current collector, an electrode layer is formed on the current collector, and a secondary battery electrode including the current collector and the electrode layer can be obtained. it can.
  • the electrode layer may be subjected to pressure treatment (pressing) using a die press or roll press.
  • pressure treatment pressing
  • the adhesion between the electrode layer and the current collector can be improved.
  • the density of the electrode layer can be increased and the secondary battery can be downsized.
  • the secondary battery of the present invention comprises the above-mentioned functional layer for a secondary battery of the present invention. More specifically, the secondary battery of the present invention includes a positive electrode, a negative electrode, a separator, and an electrolytic solution, and the above-mentioned secondary battery functional layer is provided in at least one of the positive electrode, the negative electrode, and the separator that are battery members. included. Since the secondary battery of the present invention includes the functional layer for a secondary battery of the present invention, it has a functional layer for a secondary battery having excellent safety and excellent cycle characteristics.
  • At least one of the positive electrode, the negative electrode, and the separator used in the secondary battery of the present invention has the functional layer for secondary battery of the present invention.
  • the positive electrode and the negative electrode having the functional layer for a secondary battery an electrode formed by forming an electrode layer as a secondary battery electrode layer on a current collector, or a secondary battery on the current collector
  • An electrode can be used in which a functional layer (porous membrane layer) is provided on an electrode base material formed by forming an electrode layer as a working electrode layer.
  • a separator having the secondary battery functional layer a separator obtained by providing a secondary battery functional layer (porous membrane layer) on a separator substrate can be used.
  • the electrode base material and the separator base material the same materials as those mentioned in the section of "base material" can be used.
  • the negative electrode may be a known negative electrode as long as at least one of the positive electrode used for the secondary battery, the negative electrode and the separator has the functional layer for a secondary battery of the present invention, and the known positive electrode is known.
  • the positive electrode and the negative electrode of the secondary battery may be known electrodes.
  • separator for example, those described in JP 2012-204303 A can be used as long as at least one of the positive electrode and the negative electrode used in the secondary battery has the functional layer for secondary battery of the present invention. .. Among these, it is possible to reduce the thickness of the entire separator, and thereby increase the ratio of the electrode active material in the lithium-ion secondary battery to increase the capacity per volume.
  • a microporous membrane made of a series resin polyethylene, polypropylene, polybutene, polyvinyl chloride
  • an organic electrolytic solution prepared by dissolving a supporting electrolyte in an organic solvent is usually used.
  • a lithium salt is used in a lithium ion secondary battery.
  • the lithium salt include LiPF 6 , LiAsF 6 , LiBF 4 , LiSbF 6 , LiAlCl 4 , LiClO 4 , CF 3 SO 3 Li, C 4 F 9 SO 3 Li, CF 3 COOLi, (CF 3 CO) 2 NLi. , (CF 3 SO 2 ) 2 NLi, (C 2 F 5 SO 2 ) NLi, and the like.
  • LiPF 6 , LiClO 4 , and CF 3 SO 3 Li are preferable because they are easily dissolved in a solvent and exhibit a high dissociation degree.
  • the electrolyte may be used alone or in combination of two or more. Generally, the higher the dissociation degree of the supporting electrolyte, the higher the lithium ion conductivity tends to be, so the lithium ion conductivity can be adjusted depending on the type of the supporting electrolyte.
  • the organic solvent used in the electrolytic solution is not particularly limited as long as it can dissolve the supporting electrolyte.
  • Propylene carbonate (PC), butylene carbonate (BC), ethylmethyl carbonate (EMC) and other carbonates; ⁇ -butyrolactone, methyl formate and other esters; 1,2-dimethoxyethane, tetrahydrofuran and other ethers; sulfolane, Sulfur-containing compounds such as dimethyl sulfoxide; and the like are preferably used.
  • carbonates are preferable because they have a high dielectric constant and a wide stable potential region.
  • the lower the viscosity of the solvent used the higher the lithium ion conductivity tends to be, so the lithium ion conductivity can be adjusted by the type of the solvent.
  • the concentration of the electrolyte in the electrolytic solution can be adjusted appropriately.
  • Known additives may be added to the electrolytic solution.
  • Secondary batteries for example, by stacking a positive electrode and a negative electrode via a separator, if necessary, by winding, folding, etc. into a battery container, by pouring the electrolytic solution into the battery container and sealing it. Can be manufactured. At least one of the positive electrode, the negative electrode, and the separator is the member having the functional layer for a secondary battery of the present invention.
  • the battery container may be provided with an expanded metal, a fuse, an overcurrent preventing element such as a PTC element, a lead plate, etc., if necessary, to prevent a pressure increase in the battery and an overcharge / discharge.
  • the shape of the battery may be, for example, a coin type, a button type, a sheet type, a cylindrical type, a prismatic type, a flat type, or the like.
  • Weight average molecular weight of polymer A was measured by gel permeation chromatography (GPC). First, the polymer A was added to about 5 mL of the eluent so that the solid content concentration of the polymer A was about 0.5 g / L, and gently dissolved at room temperature. After visually confirming the dissolution of the polymer A, a 0.45 ⁇ m filter was gently filtered to prepare a measurement sample. Then, a weight average molecular weight as a standard substance conversion value was calculated by creating a calibration curve with the standard substance. The measurement conditions are as follows.
  • the electrolytic solution swelling degree of the polymer A was measured by the mass change rate before and after the film swelling in the electrolytic solution.
  • the measurement conditions are as follows.
  • ⁇ Measurement conditions Polymer A was added dropwise to an aluminum dish having a diameter of 4 ⁇ 1 cm or a Teflon (registered trademark) dish so that the solid content was 0.5 g, and dried at 25 ° C. for 24 hours on a horizontal table by drying air. After that, vacuum drying was performed at a gauge pressure of ⁇ 0.08 MPa or less at 100 ° C. for 5 hours.
  • the viscosity ⁇ of the prepared secondary battery slurry composition was measured using a B-type viscometer at a temperature of 25 ° C., a spindle rotation speed of 60 rpm, and a spindle rotation time of 60 seconds, and evaluated as described below. 1 part of Polymer B (corresponding to solid content) (Examples 1 to 11 and Comparative Examples 1 and 2) or 3 parts of Polymer B (corresponding to solid content) (Example 12) of the prepared slurry composition was added. The viscosity at the point before was set as ⁇ 3.
  • the viscosity after the polymer B was added and mixed was set to ⁇ 4, and the ratio thereof was set to the slurry viscosity ratio ⁇ 5.
  • ⁇ 5 ⁇ 4 / ⁇ 3
  • ⁇ 5 is 1.0.
  • Slurry viscosity ratio ⁇ 5 is less than 1.1
  • Peel strength is 100 N / m or more
  • the laminate cell type lithium ion secondary battery was allowed to stand for 24 hours in an environment of 25 ° C. and then charged to a cell voltage of 4.25 V by a constant current method of 0.1 C, Charging / discharging operation was performed to discharge the cell voltage to 3.0 V, and the initial capacity C0 was measured. Furthermore, in an environment of 60 ° C., the cell voltage was charged to 4.25 V and discharged to a cell voltage of 3.0 V by a constant current method of 0.1 C, and charging / discharging was repeated, and the capacity C2 after 100 cycles was measured. Then, the capacity retention rate C3 was calculated according to the following formula.
  • Capacity maintenance rate C3 (C2 / C0) ⁇ 100 The larger this value is, the better the cycle characteristics are.
  • Example 1 ⁇ Preparation of Polymer A> 789 parts of ion-exchanged water was put into a glass 1 L flask, heated to a temperature of 40 ° C., and the inside of the flask was replaced with nitrogen gas having a flow rate of 100 mL / min. Next, 45 parts of acrylamide as an amide group-containing monomer, 25 parts of acrylic acid as an acid functional group-containing monomer, and 30 parts of vinyl acetate as a monomer represented by the general formula (3) are mixed. And injected into the flask. Then, 8.9 parts of a 2.5% aqueous solution of potassium persulfate as a polymerization initiator was added to the flask with a syringe.
  • the flask was opened to the air to stop the polymerization reaction, and the acid functional group-containing monomer and the molar equivalent of the monomer unit represented by the general formula (1) were added.
  • Lithium hydroxide was added as an 8% aqueous solution, and the polymerization product was adjusted to pH 7.0 while stirring at a temperature of 80 ° C. for 6 hours. Then, the polymerization product was coagulated with n-butanol and the solid content was recovered to obtain a water-soluble polymer A. The weight average molecular weight and electrolytic solution swelling degree of this polymer A were measured.
  • the content of compound X (at least one of acetic acid and acetate) relative to the solid content of polymer A was measured. The results are shown in Table 1. Further, with respect to the obtained polymer A, the content ratio of each monomer unit was measured using 1 H-NMR. The results are shown in Table 4.
  • ⁇ Preparation of Polymer B> In a 5 MPa pressure vessel A equipped with a stirrer, 3.15 parts of styrene as an aromatic monomer, 1.66 parts of 1,3-butadiene as an aliphatic conjugated diene monomer, and other monomers After adding 0.19 parts of methacrylic acid, 0.2 part of sodium lauryl sulfate as an emulsifier, 20 parts of ion-exchanged water, and 0.03 part of potassium persulfate as a polymerization initiator, and thoroughly stirring, Polymerization was initiated by heating to 60 ° C., and reaction was performed for 6 hours to obtain seed particles.
  • the mixture was heated to 75 ° C., 58.85 parts of styrene as an aromatic monomer, 34.34 parts of 1,3-butadiene as an aliphatic conjugated diene monomer, and other mono From a separate container B containing 0.81 part of methacrylic acid as a body, 0.25 part of tert-dodecyl mercaptan as a chain transfer agent and 0.35 part of sodium lauryl sulfate as an emulsifier, a mixture of these
  • the second stage polymerization was started by starting the addition to the pressure vessel A and at the same time, adding 1 part of potassium persulfate as a polymerization initiator to the pressure vessel A.
  • the above slurry composition for a secondary battery was applied on a copper foil (current collector) having a thickness of 18 ⁇ m by a comma coater so that the film thickness after drying was 105 ⁇ m and the coating amount was 10 mg / cm 2. did.
  • a copper foil current collector
  • the slurry composition for a secondary battery was transported at a speed of 0.5 m / min in an oven at a temperature of 75 ° C. for 2 minutes and further in an oven at a temperature of 120 ° C. for 2 minutes. Then, the slurry composition on the copper foil was dried to obtain a negative electrode raw material.
  • This negative electrode raw material was rolled by a roll press to obtain a negative electrode having a negative electrode mixture layer thickness of 80 ⁇ m.
  • the peel strength of the negative electrode mixture layer (adhesion strength between the negative electrode mixture layer and the copper foil (current collector)) of the obtained negative electrode was evaluated by the method described above. The results are shown in Table 1.
  • LiCoO 2 having a spinel structure as a positive electrode active material (average particle diameter 14.8 ⁇ m) 95 parts, PVDF (polyvinylidene fluoride) as a binder for the positive electrode mixture layer, 3 parts by solid equivalent, 2 parts of acetylene black (average particle size: 50 nm) as a conductive material, and 20 parts of N-methylpyrrolidone as a solvent were added and mixed to obtain a slurry composition for a lithium ion secondary battery positive electrode (secondary battery of the present invention). Not a slurry composition).
  • the obtained slurry composition for a lithium ion secondary battery positive electrode was applied by a comma coater onto an aluminum foil (current collector) having a thickness of 20 ⁇ m so that the film thickness after drying would be about 100 ⁇ m.
  • the aluminum foil coated with the slurry composition for a lithium ion secondary battery positive electrode was conveyed at a rate of 0.5 m / min in an oven at a temperature of 60 ° C. for 2 minutes and further in an oven at a temperature of 120 ° C. for 2 minutes. By doing so, the slurry composition for a lithium ion secondary battery positive electrode on the aluminum foil was dried to obtain a positive electrode raw material.
  • This positive electrode raw material was rolled by a roll press to obtain a positive electrode having a positive electrode mixture layer thickness of 70 ⁇ m.
  • a single-layer polypropylene separator (width 65 mm, length 500 mm, thickness 25 ⁇ m; manufactured by a dry method; porosity 55%) was prepared. This separator was cut out into a 5 cm ⁇ 5 cm square and used in the following lithium ion secondary battery.
  • An aluminum packaging exterior was prepared as the exterior of the battery.
  • the above positive electrode was cut into a square of 4 cm ⁇ 4 cm and arranged so that the surface of the current collector side was in contact with the aluminum packaging material exterior.
  • the square separator was placed on the surface of the positive electrode mixture layer of the positive electrode.
  • the above negative electrode was cut out into a square of 4.2 cm ⁇ 4.2 cm, and this was placed on a separator so that the surface of the negative electrode mixture layer side faces the separator.
  • vacuum drying was carried out at a gauge pressure of ⁇ 0.08 MPa or less and 60 ° C. for 10 hours using a vacuum dryer installed in an environment having a dew point of ⁇ 40 ° C. or lower.
  • Example 2 For Preparation of Polymer A, Polymer A, Polymer B and Secondary Battery were prepared in the same manner as in Example 1 except that the types and proportions of the monomers used were changed as shown in Tables 1 and 2.
  • a slurry composition was prepared, a separator was prepared, and a negative electrode, a positive electrode, and a secondary battery were manufactured. Then, various evaluations were performed in the same manner as in Example 1. The results are shown in Tables 1 to 2 and 4.
  • Example 4 The addition amount of a 2.5% aqueous solution of potassium persulfate as a polymerization initiator for the polymer A was changed from 8.9 parts to 19.8 parts, and a 2.0% aqueous solution of tetramethylethylenediamine as a polymerization accelerator was added.
  • a polymer A, a polymer B and a slurry composition for a secondary battery were prepared and a separator was prepared in the same manner as in Example 1 except that the addition amount was changed from 22.2 parts to 44.4 parts.
  • a negative electrode, a positive electrode, and a secondary battery were manufactured. Then, various evaluations were performed in the same manner as in Example 1. The results are shown in Tables 1 and 4.
  • Example 8 At the time of preparing the polymer B, a polymer A, a polymer B and a slurry composition for a secondary battery were prepared in the same manner as in Example 1 except that the ratio of the monomers used was changed as shown in Table 2. Then, a separator was prepared, and a negative electrode, a positive electrode, and a secondary battery were manufactured. Then, various evaluations were performed in the same manner as in Example 1. The results are shown in Tables 2 and 4.
  • Example 9 Polymer B was prepared as follows, except that 40 parts of methyl methacrylate, 58.5 parts of n-butyl acrylate, 0.5 parts of allyl methacrylate, and 1 part of methacrylic acid were used. In the same manner as in 1, a polymer A and a slurry composition for a secondary battery were prepared, a separator was prepared, and a negative electrode, a positive electrode and a secondary battery were manufactured. Then, various evaluations were performed in the same manner as in Example 1. The results are shown in Tables 2 and 4.
  • ⁇ Preparation of Polymer B> In a container C equipped with a stirrer, 3.15 parts of methyl methacrylate, 1.66 parts of n-butyl acrylate, 0.19 parts of methacrylic acid as another monomer, and 0.2 parts of sodium lauryl sulfate as an emulsifier. Then, 20 parts of ion-exchanged water and 0.03 part of potassium persulfate as a polymerization initiator were added, and after sufficiently stirring, the mixture was heated to 60 ° C. to start the polymerization and reacted for 6 hours to be seeded. The particles were obtained.
  • Example 10 Polymer B and secondary battery were prepared in the same manner as in Example 1, except that 100 parts of 1,3-butadiene was used and the reaction time was 20 hours as follows.
  • the slurry composition was prepared, the separator was prepared, and the negative electrode, the positive electrode, and the secondary battery were manufactured. Then, various evaluations were performed in the same manner as in Example 1. The results are shown in Tables 2 and 4.
  • ⁇ Preparation of Polymer B> In a 5 MPa pressure-resistant container A equipped with a stirrer, 100 parts of 1,3-butadiene, 0.2 part of sodium lauryl sulfate as an emulsifier, 20 parts of ion-exchanged water, and 0.03 part of potassium persulfate as a polymerization initiator. , And after sufficiently stirring, the mixture was heated to 60 ° C. to start polymerization and reacted for 6 hours. After the above reaction, the mixture was heated to 75 ° C., 1 part of potassium persulfate as a polymerization initiator was added to the pressure resistant container A, and the reaction was further performed for 18 hours.
  • Example 11 A polymer A and a slurry composition for a secondary battery were prepared and a separator was prepared in the same manner as in Example 1 except that the polymer B was prepared as follows. A secondary battery was manufactured. Then, various evaluations were performed in the same manner as in Example 1. The results are shown in Tables 2 and 4.
  • the pressure vessel A is heated to 85 ° C. and further reacted for 2 hours.
  • the polymerization conversion rate reaches 98%
  • 820.0 mmol of dichlorodimethylsilane is added as a coupling agent, and the coupling reaction is performed for 2 hours.
  • -Formed an isoprene coupling block copolymer 4000.0 ⁇ mol of methanol was added and mixed well to deactivate the active end. The reaction was stopped, and a particulate (water dispersion type) polymer B (SIS) was obtained.
  • SIS water dispersion type polymer B
  • Example 12 A negative electrode, a secondary battery porous membrane layer slurry composition (separator coating composition) were prepared, and a separator and a secondary battery were manufactured in the same manner as in Example 1 except that the following steps were carried out. , Polymer A and Polymer B were prepared to produce a positive electrode. Then, various evaluations were performed in the same manner as in Example 1. The results are shown in Tables 2 and 4.
  • the above slurry composition for a negative electrode was applied by a comma coater on a copper foil (current collector) having a thickness of 18 ⁇ m so that the film thickness after drying was 105 ⁇ m and the coating amount was 10 mg / cm 2 .
  • the copper foil coated with the negative electrode slurry composition was conveyed at a rate of 0.5 m / min in an oven at a temperature of 75 ° C. for 2 minutes, and further in an oven at a temperature of 120 ° C. for 2 minutes to obtain copper.
  • the slurry composition on the foil was dried to obtain a negative electrode raw material. This negative electrode raw material was rolled by a roll press to obtain a negative electrode having a negative electrode mixture layer thickness of 80 ⁇ m.
  • ⁇ Preparation of slurry composition for secondary battery porous membrane layer composition for coating separator> 100 parts of aluminum oxide (alumina) (volume average particle diameter: 0.5 ⁇ m) as non-conductive fine particles, 1.0 part of ammonium polycarboxylate (manufactured by Toagosei, Aron A-6114) as a dispersant, and water And were mixed. The amount of water was adjusted so that the solid content concentration was 50%. The mixture was processed using a medialess disperser to disperse aluminum oxide to obtain a slurry. 2.0 parts of Polymer A (equivalent to solid content) was added to the obtained slurry and mixed. The polymer A added was dissolved in the mixture.
  • aluminum oxide alumina
  • ammonium polycarboxylate manufactured by Toagosei, Aron A-6114
  • a secondary battery porous membrane layer slurry composition (separator coating composition) was obtained. Further, the thickening of the slurry composition for a secondary battery porous membrane layer (composition for coating a separator) was evaluated by the method described above.
  • a single-layer polyethylene separator substrate (width 250 mm, length 1000 m, thickness 12 ⁇ m) manufactured by a wet method was prepared. Then, the redispersed slurry composition for a secondary battery porous membrane layer was applied onto both surfaces of the separator substrate so that the thickness after drying was 2.5 ⁇ m by a gravure coater (coating speed: 20 m / Min). Next, the separator substrate coated with the composition for coating a separator was dried in a drying oven at 50 ° C. and wound up to produce a separator having a porous membrane layer (functional layer) on both sides of the separator substrate. This separator was cut out into a 5 cm ⁇ 5 cm square and used for manufacturing a secondary battery.
  • An aluminum packaging exterior was prepared as the exterior of the battery.
  • the above positive electrode was cut into a square of 4 cm ⁇ 4 cm and arranged so that the surface of the current collector side was in contact with the aluminum packaging material exterior.
  • the square separator was placed on the surface of the positive electrode mixture layer of the positive electrode.
  • the above negative electrode was cut out into a square of 4.2 cm ⁇ 4.2 cm, and this was placed on a separator so that the surface of the negative electrode mixture layer side faces the separator.
  • Example 13 In the same manner as in Example 1 except that the polymer B was not added during the preparation of the slurry composition for a secondary battery and the 3.0 parts corresponding to the solid content of the polymer A was changed to 4.0 parts. Then, a polymer A and a slurry composition for a secondary battery were prepared, a separator was prepared, and a negative electrode, a positive electrode and a secondary battery were manufactured. Then, various evaluations were performed in the same manner as in Example 1. The results are shown in Tables 2 and 4.
  • ⁇ Preparation of Polymer A 789 parts of ion-exchanged water was put into a glass 1 L flask, heated to a temperature of 40 ° C., and the inside of the flask was replaced with nitrogen gas having a flow rate of 100 mL / min. Next, 65 parts of acrylamide as an amide group-containing monomer, 10 parts of acrylic acid as an acid functional group-containing monomer, 20 parts of 2-hydroxyethyl acrylate as another monomer, and 5 parts of methyl acrylate are mixed. Then, it was injected into the flask.
  • AAm indicates acrylamide
  • AA indicates acrylic acid
  • VA indicates vinyl acetate
  • HSA means 2-hydroxyethyl acrylate
  • Swelling degree indicates the degree of swelling of the electrolytic solution
  • Mw indicates a weight average molecular weight
  • LA represents lithium acetate
  • MA represents methyl acrylate
  • BA represents n-butyl acrylate
  • BD represents 1,3-butadiene
  • IP indicates isoprene
  • ST indicates styrene
  • MAA indicates methacrylic acid
  • MMA means methyl methacrylate
  • AMA means allyl methacrylate
  • AG indicates artificial graphite
  • Copper foil coat indicates that “a copper foil is coated with the negative electrode slurry composition”
  • Separator coat means that "a polyethylene separator base material is coated with a slurry composition for a porous membrane layer”
  • LIB indicates a lithium i
  • the binder composition for secondary batteries which can produce the secondary battery excellent in cycling characteristics can be provided. Further, according to the present invention, it is possible to provide a slurry composition for a secondary battery, which can produce a secondary battery having excellent cycle characteristics. Further, according to the present invention, it is possible to provide a functional layer for a secondary battery, which enables the production of a secondary battery having excellent cycle characteristics. In addition, according to the present invention, it is possible to provide an electrode layer for a secondary battery, which can produce a secondary battery having excellent cycle characteristics. Moreover, according to the present invention, a secondary battery having excellent cycle characteristics can be provided.
  • a binder composition for a secondary battery capable of producing a secondary battery having excellent cycle characteristics can be efficiently produced. Further, according to the present invention, it is possible to efficiently manufacture a secondary battery functional layer capable of manufacturing a secondary battery having excellent cycle characteristics.

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Abstract

The purpose of the present invention is to provide a binder composition for a secondary battery with which a secondary battery having excellent cycle characteristics can be manufactured. This binder composition comprises a water-soluble polymer A and a solvent. The polymer A comprises an amide group-containing monomeric unit, an acid functional group-containing monomeric unit, and a monomeric unit represented by general formula (1). In general formula (1), R1 is a chemical single bond, a methylene group, an ethylene group, a 1,2-propylene group, or a 1,3-propylene group, and R2 and R3 are each independently a hydrogen atom, a methyl group, an ethyl group, a propyl group, or an isopropyl group.

Description

二次電池用バインダー組成物およびその製造方法、二次電池用スラリー組成物、二次電池用機能層およびその製造方法、二次電池用電極層、並びに二次電池Binder composition for secondary battery and manufacturing method thereof, slurry composition for secondary battery, functional layer for secondary battery and manufacturing method thereof, electrode layer for secondary battery, and secondary battery
　本発明は、二次電池用バインダー組成物およびその製造方法、二次電池用スラリー組成物、二次電池用機能層およびその製造方法、二次電池用電極層、並びに二次電池に関するものである。 TECHNICAL FIELD The present invention relates to a binder composition for a secondary battery and a manufacturing method thereof, a slurry composition for a secondary battery, a functional layer for a secondary battery and a manufacturing method thereof, an electrode layer for a secondary battery, and a secondary battery. ..
　リチウムイオン二次電池などの非水系二次電池（以下、「二次電池」と略記する場合がある）は、小型で軽量、且つエネルギー密度が高く、更に繰り返し充放電が可能という特性があり、幅広い用途に使用されている。そして二次電池は、一般に、電極層を有する電極（正極、負極）、および、正極と負極とを隔離して正極と負極との間の短絡を防ぐセパレータなどの電池部材を備えている。また近年では、耐熱性や強度の向上を目的とした多孔膜層や、電池部材間の接着性の向上を目的とした接着層を備える電池部材が使用されている。 A non-aqueous secondary battery such as a lithium ion secondary battery (hereinafter, may be abbreviated as “secondary battery”) has a characteristic that it is small and lightweight, has a high energy density, and can be repeatedly charged and discharged. It is used for a wide range of purposes. The secondary battery generally includes electrodes (a positive electrode and a negative electrode) having an electrode layer, and a battery member such as a separator that separates the positive electrode and the negative electrode to prevent a short circuit between the positive electrode and the negative electrode. Further, in recent years, a battery member having a porous membrane layer for the purpose of improving heat resistance and strength and an adhesive layer for improving the adhesiveness between battery members has been used.
　ここで、上述した電池部材中の成分や、電池部材同士を接着させること等を目的として、結着性を有する結着材が使用されている。そして二次電池の更なる性能向上を達成すべく、電極合材層（正極合材層、負極合材層）等の電極層、多孔膜層、並びに接着層等の機能層の形成に用いられる結着材の改良が試みられている（例えば、特許文献１～３参照）。 ▽ Here, a binder having a binding property is used for the purpose of adhering the above-mentioned components in the battery member or the battery members to each other. Then, in order to further improve the performance of the secondary battery, it is used for forming electrode layers such as electrode mixture layers (positive electrode mixture layer, negative electrode mixture layer), porous membrane layers, and functional layers such as adhesive layers. Attempts have been made to improve the binder (see, for example, Patent Documents 1 to 3).
　特許文献１では、（メタ）アクリルアミドに由来する繰り返し単位を含有する水溶性重合体を含有する蓄電デバイス用スラリーを用いることで、集電体やセパレータとの密着性に優れた層を形成できると共に、充放電特性に優れた蓄電デバイスを製造する技術が提案されている。
　特許文献２では、（メタ）アクリルアミドに由来する繰り返し単位を含有する水溶性重合体と、所定の大きさの活物質と、液状媒体と、を含む蓄電デバイス電極用スラリーを用いることで、集電体やセパレータとの密着性に優れた層を形成できると共に、充放電特性に優れた蓄電デバイスを製造する技術が提案されている。
　特許文献３では、（ｉ）不飽和カルボン酸類の重合性単量体と、（ｉｉ）（メタ）アクリルアミドと、（ｉｉｉ）ビニル単量体とを含む単量体群を重合してなる水溶性樹脂（ａ）と、ビニル単量体を乳化重合してなる有機粒子（ｂ）とを含む電気化学セル用アクリル系水分散体を用いることで、金属集電体に対して十分な密着性を有し、かつ電気化学的に安定で電気化学セルが膨れにくく、従来の静電気容量・内部抵抗を維持しながら、特に二次電池のサイクル特性を向上させる技術が提案されている。 In Patent Document 1, by using a slurry for an electricity storage device containing a water-soluble polymer containing a repeating unit derived from (meth) acrylamide, it is possible to form a layer having excellent adhesion to a current collector or a separator. A technique for manufacturing an electricity storage device having excellent charge / discharge characteristics has been proposed.
In Patent Document 2, by using a slurry for an electricity storage device electrode containing a water-soluble polymer containing a repeating unit derived from (meth) acrylamide, an active material having a predetermined size, and a liquid medium, current collection is performed. Techniques have been proposed for producing a power storage device that can form a layer having excellent adhesion to a body or a separator and that has excellent charge / discharge characteristics.
In Patent Document 3, water-soluble obtained by polymerizing a monomer group including (i) a polymerizable monomer of an unsaturated carboxylic acid, (ii) (meth) acrylamide, and (iii) a vinyl monomer. Sufficient adhesion to a metal current collector can be obtained by using an acrylic water dispersion for an electrochemical cell containing a resin (a) and organic particles (b) obtained by emulsion-polymerizing a vinyl monomer. There is proposed a technique which has electrochemical stability and is electrochemically stable, and which does not cause swelling of the electrochemical cell and maintains the conventional electrostatic capacity and internal resistance, and particularly improves the cycle characteristics of the secondary battery.
特開２０１５－０２２９５６号公報Japanese Patent Laid-Open No. 2015-022956 特開２０１５－１０６４８８号公報JP, 2005-106488, A 特許第５９４３６０２号公報Japanese Patent No. 5943602
　しかしながら、上記従来の結着材を用いて作製される二次電池は、サイクル特性が十分ではなかった。そのため、サイクル特性に優れる二次電池を作製可能な二次電池用バインダー組成物を提供することが求められている。 However, the cycle characteristics of the secondary battery manufactured using the above conventional binder were not sufficient. Therefore, it is required to provide a binder composition for a secondary battery, which can produce a secondary battery having excellent cycle characteristics.
　そこで、本発明者は、サイクル特性に優れる二次電池を作製可能な二次電池用バインダー組成物を提供することを目的として鋭意検討を行った。そこで、本発明者は検討を重ね、所定の重合体Ａおよび溶媒を含むバインダー組成物を用いれば、サイクル特性に優れる二次電池を作製可能であることを見出し、本発明を完成させた。 Therefore, the present inventor has conducted earnest studies for the purpose of providing a binder composition for a secondary battery capable of producing a secondary battery having excellent cycle characteristics. Therefore, the present inventor has conducted extensive studies and found that a secondary battery having excellent cycle characteristics can be produced by using a binder composition containing a predetermined polymer A and a solvent, and completed the present invention.
　即ち、この発明は、上記課題を有利に解決することを目的とするものであり、本発明の二次電池用バインダー組成物は、水溶解型の重合体Ａおよび溶媒を含む二次電池用バインダー組成物であって、前記重合体Ａが、アミド基含有単量体単位、酸官能基含有単量体単位、および下記一般式（１）で表される単量体単位を含む、ことを特徴とする。
Figure JPOXMLDOC01-appb-C000005
 （一般式（１）中、Ｒ1は、化学的な単結合、メチレン基、エチレン基、１，２－プロピレン基、または１，３－プロピレン基を表し、Ｒ2およびＲ3は、それぞれ独立して、水素原子、メチル基、エチル基、プロピル基、またはイソプロピル基を表す。）
　このように、アミド基含有単量体単位、酸官能基含有単量体単位、および上記一般式（１）で表される単量体単位を含む重合体Ａと、溶媒とを含む二次電池用バインダー組成物を用いれば、サイクル特性に優れる二次電池を作製可能である。
　なお、本発明において「単量体単位を含む」とは、「その単量体を用いて得た重合体中に単量体由来の繰り返し単位が含まれている」ことを意味する。また、本発明において、「水溶解型の重合体」は、温度９０℃において重合体０．５ｇを１００ｇの水に溶解した際に、重合体固形分中の不溶分が３０質量％未満となる重合体を意味する。また、本発明において、複数種類の単量体を共重合して製造される重合体において、ある単量体を重合して形成される単量体単位の前記重合体における割合は、特に断らない限り、通常は、その重合体の重合に用いる全単量体に占める当該の単量体の比率(仕込み比)と概ね一致する。さらに、本発明において、「アミド基含有単量体単位の含有割合」、「酸官能基含有単量体単位の含有割合」および「一般式（１）で表される単量体単位の含有割合」は、1Ｈ－ＮＭＲなどの核磁気共鳴（ＮＭＲ）法を用いて測定することができる。 That is, this invention aims at solving the above-mentioned subject advantageously, and the binder composition for secondary batteries of this invention is a binder for secondary batteries containing the water-soluble polymer A and a solvent. A composition, wherein the polymer A contains an amide group-containing monomer unit, an acid functional group-containing monomer unit, and a monomer unit represented by the following general formula (1): And
Figure JPOXMLDOC01-appb-C000005
 (In the general formula (1), R 1 represents a chemical single bond, a methylene group, an ethylene group, a 1,2-propylene group, or a 1,3-propylene group, and R 2 and R 3 are each independently. And represents a hydrogen atom, a methyl group, an ethyl group, a propyl group, or an isopropyl group.)
Thus, the secondary battery containing the solvent and the polymer A containing the amide group-containing monomer unit, the acid functional group-containing monomer unit, and the monomer unit represented by the general formula (1). By using the binder composition for a secondary battery, a secondary battery having excellent cycle characteristics can be manufactured.
In addition, in the present invention, "containing a monomer unit" means "a repeating unit derived from a monomer is contained in a polymer obtained by using the monomer". Further, in the present invention, the “water-soluble polymer” has an insoluble content in the polymer solid content of less than 30% by mass when 0.5 g of the polymer is dissolved in 100 g of water at a temperature of 90 ° C. Means a polymer. Further, in the present invention, in the polymer produced by copolymerizing a plurality of kinds of monomers, the ratio of the monomer unit formed by polymerizing a certain monomer in the polymer is not particularly specified. As long as it is, the ratio (feeding ratio) of the monomer to all the monomers used for the polymerization of the polymer is almost the same. Further, in the present invention, "content ratio of amide group-containing monomer unit", "content ratio of acid functional group-containing monomer unit" and "content ratio of monomer unit represented by general formula (1)" Can be measured using a nuclear magnetic resonance (NMR) method such as 1 H-NMR.
　ここで、本発明の二次電池用バインダー組成物は、下記一般式（２）で表される化合物Ｘをさらに含み、前記重合体Ａの固形分に対する前記化合物Ｘの含有割合が１００質量ｐｐｍ以上であることが好ましい。
Figure JPOXMLDOC01-appb-C000006
 （一般式（２）中、Ｘは、水素原子またはアルカリ金属原子を表し、Ｒ4は、炭素数１～５のアルキル基を表す。）
　重合体Ａの固形分に対する上記一般式（２）で表される化合物Ｘの含有割合が１００質量ｐｐｍ以上であれば、二次電池用スラリー組成物が増粘するのを抑制することができる。
　なお、本発明において「重合体Ａの固形分に対する化合物Ｘの含有割合」は、高速液体クロマトグラフ（ＨＰＬＣ）を用いて測定することができる。 Here, the binder composition for a secondary battery of the present invention further contains a compound X represented by the following general formula (2), and the content ratio of the compound X to the solid content of the polymer A is 100 mass ppm or more. Is preferred.
Figure JPOXMLDOC01-appb-C000006
 (In the general formula (2), X represents a hydrogen atom or an alkali metal atom, and R 4 represents an alkyl group having 1 to 5 carbon atoms.)
When the content ratio of the compound X represented by the general formula (2) with respect to the solid content of the polymer A is 100 mass ppm or more, it is possible to prevent the slurry composition for a secondary battery from thickening.
In addition, in this invention, "content ratio of the compound X with respect to the solid content of the polymer A" can be measured using a high performance liquid chromatograph (HPLC).
　また、本発明の二次電池用バインダー組成物において、前記重合体Ａの重量平均分子量が１００万以上であることが好ましい。
　重合体Ａの重量平均分子量が１００万以上であれば、バインダー組成物を用いて形成される機能層のバルク強度を向上させて、ピール強度を向上させることができる。
　なお、本発明において、「重合体Ａの重量平均分子量」は、実施例に記載の方法により測定することができる。 Further, in the binder composition for a secondary battery of the present invention, the weight average molecular weight of the polymer A is preferably 1,000,000 or more.
When the weight average molecular weight of the polymer A is 1,000,000 or more, the bulk strength of the functional layer formed using the binder composition can be improved and the peel strength can be improved.
In the present invention, the “weight average molecular weight of the polymer A” can be measured by the method described in Examples.
　また、本発明の二次電池用バインダー組成物において、前記重合体Ａの電解液膨潤度が１００質量％以上１５０質量％以下であることが好ましい。
　重合体Ａの電解液膨潤度が１００質量％以上１５０質量％以下であれば、サイクル特性に優れる二次電池を確実に作製することができる。
　なお、本発明において、「重合体Ａの電解液膨潤度」は、重合体Ａのフィルムを電解液に浸漬させ、その浸漬前後の質量増加率で測定することができる。より具体的には、「重合体Ａの電解液膨潤度」は、実施例に記載の方法により測定することができる。 Further, in the binder composition for a secondary battery of the present invention, it is preferable that the electrolytic solution swelling degree of the polymer A is 100% by mass or more and 150% by mass or less.
When the electrolytic solution swelling degree of the polymer A is 100% by mass or more and 150% by mass or less, a secondary battery having excellent cycle characteristics can be reliably manufactured.
In the present invention, the “degree of swelling of polymer A in an electrolytic solution” can be measured by immersing a film of polymer A in an electrolytic solution and measuring a mass increase rate before and after the immersion. More specifically, the “degree of electrolyte solution swelling of the polymer A” can be measured by the method described in Examples.
　また、本発明の二次電池用バインダー組成物において、前記重合体Ａは、前記アミド基含有単量体単位を２０質量％以上６０質量％以下含み、前記酸官能基含有単量体単位を１０質量％以上４５質量％以下含み、前記一般式（１）で表される単量体単位を５質量％以上４０質量％以下含むことが好ましい。
　重合体Ａが、アミド基含有単量体単位を２０質量％以上６０質量％以下含み、酸官能基含有単量体単位を１０質量％以上４５質量％以下含み、一般式（１）で表される単量体単位を５質量％以上４０質量％以下含めば、二次電池用スラリー組成物の増粘を抑制し、ピール強度を向上させ、得られた二次電池のサイクル特性をより向上させることができる。 Further, in the binder composition for a secondary battery of the present invention, the polymer A contains 20% by mass or more and 60% by mass or less of the amide group-containing monomer unit and 10% by weight of the acid functional group-containing monomer unit. It is preferable that the content of the monomer unit represented by the general formula (1) is 5% by mass or more and 40% by mass or less.
Polymer A contains amide group-containing monomer units in an amount of 20% by mass or more and 60% by mass or less, and acid functional group-containing monomer units in an amount of 10% by mass or more and 45% by mass or less, and is represented by the general formula (1). When the content of the monomer unit is 5% by mass or more and 40% by mass or less, the viscosity of the slurry composition for a secondary battery is suppressed, the peel strength is improved, and the cycle characteristics of the obtained secondary battery are further improved. be able to.
　また、本発明の二次電池用バインダー組成物において、水分散体型の重合体Ｂをさらに含み、前記重合体Ｂが、脂肪族共役ジエン単量体単位を１０質量％以上９０質量％以下含み、芳香族単量体単位を１０質量％以上９０質量％以下含むことが好ましい。
　水分散体型の重合体Ｂをさらに含み、重合体Ｂが、脂肪族共役ジエン単量体単位を１０質量％以上９０質量％以下含み、芳香族単量体単位を１０質量％以上９０質量％以下含めば、ピール強度を向上させ、得られた二次電池のサイクル特性をより向上させることができる。
　なお、本発明において、「水分散体型の重合体」は、温度９０℃において重合体０．５ｇを１００ｇの水に溶解した際に、重合体固形分中の不溶分が３０質量％以上となる重合体を意味する。また、本発明において、「脂肪族共役ジエン単量体単位の含有割合」および「芳香族単量体単位の含有割合」は、1Ｈ－ＮＭＲなどの核磁気共鳴（ＮＭＲ）法を用いて測定することができる。 Moreover, in the binder composition for a secondary battery of the present invention, the polymer B of an aqueous dispersion type is further included, and the polymer B contains an aliphatic conjugated diene monomer unit in an amount of 10% by mass or more and 90% by mass or less, It is preferable that the aromatic monomer unit is contained in an amount of 10% by mass or more and 90% by mass or less.
The polymer B further comprises an aqueous dispersion type polymer B, and the polymer B contains 10% by mass or more and 90% by mass or less of an aliphatic conjugated diene monomer unit and 10% by mass or more and 90% by mass or less of an aromatic monomer unit. If included, the peel strength can be improved and the cycle characteristics of the obtained secondary battery can be further improved.
In the present invention, the “water-dispersion type polymer” has an insoluble content of 30% by mass or more in the polymer solid content when 0.5 g of the polymer is dissolved in 100 g of water at a temperature of 90 ° C. Means a polymer. In addition, in the present invention, the “content ratio of the aliphatic conjugated diene monomer unit” and the “content ratio of the aromatic monomer unit” are measured by a nuclear magnetic resonance (NMR) method such as 1 H-NMR. can do.
　そして、この発明は、上記課題を有利に解決することを目的とするものであり、本発明の二次電池用スラリー組成物は、上述した何れかの二次電池用バインダー組成物を含むことを特徴とする。
　このように、上述の何れかの二次電池用バインダー組成物を含む二次電池用スラリー組成物を用いれば、サイクル特性に優れる二次電池を作製可能である。 And this invention aims at solving the said subject advantageously, and the slurry composition for secondary batteries of this invention contains the binder composition for secondary batteries in any one of the above. Characterize.
As described above, by using the slurry composition for a secondary battery containing any one of the binder compositions for a secondary battery described above, a secondary battery having excellent cycle characteristics can be manufactured.
　また、本発明の二次電池用スラリー組成物は、非導電性微粒子をさらに含むことができる。 The secondary battery slurry composition of the present invention may further include non-conductive fine particles.
　また、本発明の二次電池用スラリー組成物は、電極活物質をさらに含むことができる。 The secondary battery slurry composition of the present invention may further include an electrode active material.
　そして、この発明は、上記課題を有利に解決することを目的とするものであり、本発明の二次電池用機能層は、基材上に、上述した何れかの二次電池用スラリー組成物を用いて形成されたことを特徴とする。
　このように、基材上に、上述した何れかの二次電池用スラリー組成物を用いて形成された二次電池用機能層を有する二次電池は、サイクル特性に優れている。 And this invention aims at solving the said subject advantageously, and the functional layer for secondary batteries of this invention is a slurry composition for secondary batteries of any one of the above-mentioned on a base material. It is characterized by being formed using.
As described above, the secondary battery having the functional layer for a secondary battery formed by using the slurry composition for a secondary battery described above on the base material has excellent cycle characteristics.
　そして、この発明は、上記課題を有利に解決することを目的とするものであり、本発明の二次電池用電極層は、集電体上に、電極活物質をさらに含む二次電池用スラリー組成物を用いて形成されたことを特徴とする。
　このように、集電体上に、上述した二次電池用スラリー組成物を用いて形成された二次電池用電極層を有する二次電池は、サイクル特性に優れている。 And this invention aims at solving the said subject advantageously, the secondary battery electrode layer of this invention WHEREIN: The slurry for secondary batteries which further contains an electrode active material on a collector. It is characterized by being formed using the composition.
As described above, the secondary battery having the secondary battery electrode layer formed by using the above-described secondary battery slurry composition on the current collector has excellent cycle characteristics.
　そして、この発明は、上記課題を有利に解決することを目的とするものであり、本発明の二次電池は、正極、負極、セパレータおよび電解液を備える二次電池であって、前記正極、前記負極および前記セパレータの少なくともいずれかが、上述した二次電池用機能層を有することを特徴とする。
　このように、正極、負極およびセパレータの少なくともいずれかが、上述した二次電池用機能層を有することで、サイクル特性に優れた二次電池を提供することができる。 Then, the present invention is intended to advantageously solve the above problems, the secondary battery of the present invention is a secondary battery comprising a positive electrode, a negative electrode, a separator and an electrolytic solution, the positive electrode, At least one of the negative electrode and the separator has the functional layer for a secondary battery described above.
As described above, since at least one of the positive electrode, the negative electrode, and the separator has the above-described functional layer for secondary battery, it is possible to provide a secondary battery having excellent cycle characteristics.
　そして、この発明は、上記課題を有利に解決することを目的とするものであり、本発明の二次電池用バインダー組成物の製造方法は、アミド基含有単量体単位、酸官能基含有単量体単位、および下記一般式（１）で表される単量体単位を含む水溶解型の重合体Ａ、並びに、溶媒を含む二次電池用バインダー組成物を製造する二次電池用バインダー組成物の製造方法であって、アミド基含有単量体、酸官能基含有単量体、および下記一般式（３）で表される単量体を共重合して、共重合体を得る共重合工程と、前記共重合体をけん化して、前記重合体Ａを得るけん化工程とを含むことを特徴とする。
Figure JPOXMLDOC01-appb-C000007
 （一般式（１）中、Ｒ1は、化学的な単結合、メチレン基、エチレン基、１，２－プロピレン基、または１，３－プロピレン基を表し、Ｒ2およびＲ3は、それぞれ独立して、水素原子、メチル基、エチル基、プロピル基、またはイソプロピル基を表す。）
Figure JPOXMLDOC01-appb-C000008
 （一般式（３）中、Ｒ1は、化学的な単結合、メチレン基、エチレン基、１，２－プロピレン基、または１，３－プロピレン基を表し、Ｒ4は、炭素数１～５のアルキル基を表す。）
　このように、共重合工程とけん化工程とを含む二次電池用バインダー組成物の製造方法用いることで、サイクル特性に優れる二次電池を作製可能な二次電池用バインダー組成物を効率良く製造することができる。 And this invention aims at solving the above-mentioned subject advantageously, and the manufacturing method of the binder composition for secondary batteries of this invention is an amide group containing monomer unit, an acid functional group containing unit. A binder composition for a secondary battery, which comprises a water-soluble polymer A containing a monomer unit and a monomer unit represented by the following general formula (1), and a binder composition for a secondary battery containing a solvent. A method for producing a copolymer, comprising copolymerizing an amide group-containing monomer, an acid functional group-containing monomer, and a monomer represented by the following general formula (3) to obtain a copolymer: A saponification step of saponifying the copolymer to obtain the polymer A.
Figure JPOXMLDOC01-appb-C000007
 (In the general formula (1), R 1 represents a chemical single bond, a methylene group, an ethylene group, a 1,2-propylene group, or a 1,3-propylene group, and R 2 and R 3 are each independently. And represents a hydrogen atom, a methyl group, an ethyl group, a propyl group, or an isopropyl group.)
Figure JPOXMLDOC01-appb-C000008
 (In the general formula (3), R 1 represents a chemical single bond, a methylene group, an ethylene group, a 1,2-propylene group or a 1,3-propylene group, and R 4 represents a carbon number of 1 to 5 Represents the alkyl group of.)
As described above, by using the method for producing a binder composition for a secondary battery including the copolymerization step and the saponification step, a binder composition for a secondary battery capable of producing a secondary battery having excellent cycle characteristics can be efficiently produced. be able to.
　そして、この発明は、上記課題を有利に解決することを目的とするものであり、本発明の二次電池用機能層の製造方法は、基材上に、上述した何れかの二次電池用スラリー組成物を塗布する塗布工程と、前記塗布工程において塗布された二次電池用スラリー組成物を真空乾燥する真空乾燥工程と、を含むことを特徴とする。
　このように、塗布工程と真空乾燥工程とを含む二次電池用機能層の製造方法用いることで、サイクル特性に優れる二次電池を作製可能な二次電池用機能層を効率良く製造することができる。
　なお、本発明において、「真空乾燥」とは、８０ｋＰａ以下、４０℃以上の温度で、水などの溶媒を除去する乾燥を行うことをいう。 And this invention aims at solving the said subject advantageously, The manufacturing method of the functional layer for secondary batteries of this invention WHEREIN: For any of the above-mentioned secondary batteries on a base material. It is characterized by including a coating step of coating the slurry composition and a vacuum drying step of vacuum-drying the secondary battery slurry composition coated in the coating step.
As described above, by using the method for producing a secondary battery functional layer including a coating step and a vacuum drying step, a secondary battery functional layer capable of producing a secondary battery having excellent cycle characteristics can be efficiently produced. it can.
In the present invention, “vacuum drying” means performing drying for removing a solvent such as water at a temperature of 80 kPa or lower and 40 ° C. or higher.
　本発明によれば、サイクル特性に優れる二次電池を作製可能な二次電池用バインダー組成物を提供することができる。
　また、本発明によれば、サイクル特性に優れる二次電池を作製可能な二次電池用スラリー組成物を提供することができる。
　また、本発明によれば、サイクル特性に優れる二次電池を作製可能な二次電池用機能層を提供することができる。
　また、本発明によれば、サイクル特性に優れる二次電池を作製可能な二次電池用電極層を提供することができる。
　また、本発明によれば、サイクル特性に優れる二次電池を提供することができる。
　また、本発明によれば、サイクル特性に優れる二次電池を作製可能な二次電池用バインダー組成物を効率良く製造することができる。
　さらに、本発明によれば、サイクル特性に優れる二次電池を作製可能な二次電池用機能層を効率良く製造することができる。 ADVANTAGE OF THE INVENTION According to this invention, the binder composition for secondary batteries which can produce the secondary battery excellent in cycling characteristics can be provided.
Further, according to the present invention, it is possible to provide a slurry composition for a secondary battery, which can produce a secondary battery having excellent cycle characteristics.
Further, according to the present invention, it is possible to provide a functional layer for a secondary battery, which enables the production of a secondary battery having excellent cycle characteristics.
In addition, according to the present invention, it is possible to provide an electrode layer for a secondary battery, which can produce a secondary battery having excellent cycle characteristics.
Moreover, according to the present invention, a secondary battery having excellent cycle characteristics can be provided.
Further, according to the present invention, a binder composition for a secondary battery capable of producing a secondary battery having excellent cycle characteristics can be efficiently produced.
Further, according to the present invention, it is possible to efficiently manufacture a secondary battery functional layer capable of manufacturing a secondary battery having excellent cycle characteristics.
　以下、本発明の実施形態について詳細に説明する。
　ここで、本発明の二次電池用バインダー組成物は、例えば、電極における集電体上に形成される電極層や、当該電極層の更に上（すなわち電極基材の上）やセパレータ基材の上に形成される多孔膜層の形成に用いられるものである。そして、本発明の二次電池用スラリー組成物は、本発明の二次電池用バインダー組成物を含み、本発明の二次電池用機能層や本発明の二次電池用電極層を調製する際の材料として用いられる。また、本発明の二次電池用機能層は、本発明の二次電池用スラリー組成物を用いて調製され、例えばセパレータや電極の一部を構成する。本発明の二次電池用電極層は、本発明の二次電池用スラリー組成物を用いて調製され、電極の一部を構成する。そして、本発明の二次電池は、本発明の二次電池用機能層（電極層、接着層、または多孔膜層）を備えるものである。 Hereinafter, embodiments of the present invention will be described in detail.
Here, the binder composition for a secondary battery of the present invention is, for example, an electrode layer formed on a current collector in an electrode, further above the electrode layer (that is, on an electrode base material) or a separator base material. It is used for forming the porous membrane layer formed on the above. When the slurry composition for a secondary battery of the present invention contains the binder composition for a secondary battery of the present invention, when preparing the functional layer for a secondary battery of the present invention or the electrode layer for a secondary battery of the present invention It is used as a material. The functional layer for a secondary battery of the present invention is prepared using the slurry composition for a secondary battery of the present invention and constitutes, for example, a separator or a part of an electrode. The electrode layer for a secondary battery of the present invention is prepared using the slurry composition for a secondary battery of the present invention, and constitutes a part of the electrode. The secondary battery of the present invention includes the secondary battery functional layer of the present invention (electrode layer, adhesive layer, or porous membrane layer).
（二次電池用バインダー組成物）
　本発明の二次電池用バインダー組成物は、重合体Ａ、溶媒を含有し、任意に、重合体Ｂ、化合物Ｘ、その他の成分を含有する。ここで、前記重合体Ａは、アミド基含有単量体単位、酸官能基含有単量体単位、および一般式（１）で表される単量体単位を含む。
　そして、本発明の二次電池用バインダー組成物を用いることで、サイクル特性に優れる二次電池を作製可能である。加えて本発明の二次電池用バインダー組成物中の重合体Ａは、優れた結着性を有するものであるため、本発明の二次電池用バインダー組成物は、機能層用バインダー組成物（電極層用バインダー組成物、接着層用バインダー組成物、または多孔膜層用バインダー組成物）としても良好に使用することができる。以下では、本発明の二次電池用バインダー組成物について、当該二次電池用バインダー組成物を機能層（電極層、接着層、または多孔膜層）の形成に用いる場合を例に挙げて説明する。 (Binder composition for secondary battery)
The binder composition for a secondary battery of the present invention contains polymer A and a solvent, and optionally polymer B, compound X, and other components. Here, the polymer A contains an amide group-containing monomer unit, an acid functional group-containing monomer unit, and a monomer unit represented by the general formula (1).
Then, by using the binder composition for a secondary battery of the present invention, a secondary battery having excellent cycle characteristics can be manufactured. In addition, since the polymer A in the binder composition for a secondary battery of the present invention has excellent binding properties, the binder composition for a secondary battery of the present invention is a binder composition for a functional layer ( It can also be favorably used as a binder composition for an electrode layer, a binder composition for an adhesive layer, or a binder composition for a porous film layer). Hereinafter, the binder composition for a secondary battery of the present invention will be described by taking as an example the case where the binder composition for a secondary battery is used for forming a functional layer (electrode layer, adhesive layer, or porous film layer). .
＜重合体Ａ＞
　重合体Ａは、アミド基含有単量体単位と、酸官能基含有単量体単位と、一般式（１）で表される単量体単位とを含み、任意に、アミド基含有単量体単位、酸官能基含有単量体単位および一般式（１）で表される単量体単位以外の単量体単位を含んでいてもよい。重合体Ａがこのような単量体組成を有することで、サイクル特性に優れる二次電池を作製可能な二次電池用スラリー組成物を調製することができる。
　また、重合体Ａは、水溶解型である。重合体Ａが水溶解型であることにより、スラリー組成物の粘性を制御することができ、均一な膜厚を有する機能層（電極層、接着層、または多孔膜層）が得られる。 <Polymer A>
Polymer A contains an amide group-containing monomer unit, an acid functional group-containing monomer unit, and a monomer unit represented by the general formula (1), and optionally an amide group-containing monomer. A unit, a monomer unit containing an acid functional group, and a monomer unit other than the monomer unit represented by the general formula (1) may be contained. When the polymer A has such a monomer composition, it is possible to prepare a secondary battery slurry composition capable of producing a secondary battery having excellent cycle characteristics.
Further, the polymer A is a water-soluble type. When the polymer A is water-soluble, the viscosity of the slurry composition can be controlled, and a functional layer (electrode layer, adhesive layer, or porous film layer) having a uniform film thickness can be obtained.
［アミド基含有単量体単位］
　アミド基含有単量体単位を形成し得るアミド基含有単量体としては、メタクリルアミド、アクリルアミド、ジメチルアクリルアミド、ジエチルアクリルアミド、ダイアセトンアクリルアミド、ヒドロキシエチルアクリルアミド、ヒドロキシメチルアクリルアミド、ヒドロキシプロピルアクリルアミド、ヒドロキシブチルアクリルアミド、などが挙げられる。これらは、１種類を単独で用いてもよく、２種類以上を任意の比率で組み合わせて用いてもよい。そしてこれらの中でも、スラリー組成物の粘性の観点から、アクリルアミドが好ましい。 [Amido group-containing monomer unit]
Examples of the amide group-containing monomer capable of forming the amide group-containing monomer unit include methacrylamide, acrylamide, dimethyl acrylamide, diethyl acrylamide, diacetone acrylamide, hydroxyethyl acrylamide, hydroxymethyl acrylamide, hydroxypropyl acrylamide, hydroxybutyl acrylamide. , And so on. These may be used individually by 1 type and may be used in combination of 2 or more types by arbitrary ratios. Of these, acrylamide is preferable from the viewpoint of the viscosity of the slurry composition.
　そして、重合体Ａ中におけるアミド基含有単量体単位の含有量（重合体Ａに含まれる全単量体単位中に占めるアミド基含有単量体単位の割合）は、２０質量％以上であることが好ましく、２５質量％以上であることがより好ましく、３５質量％以上であることが特に好ましく、また、６０質量％以下であることが好ましく、５５質量％以下であることがより好ましく、５３質量％以下であることが特に好ましい。重合体Ａ中におけるアミド基含有単量体単位の含有量を上記下限値以上とすることで、塗工表面での欠陥を低減して、バインダー組成物を用いて形成される電極またはセパレータを備える二次電池のサイクル特性をより向上させることができる。一方、重合体Ａ中におけるアミド基含有単量体単位の含有量を上記上限値以下とすることで、調製した二次電池用スラリー組成物を用いて形成した機能層（電極層、接着層、または多孔膜層）のピール強度を向上させることができる。 The content of the amide group-containing monomer unit in the polymer A (the proportion of the amide group-containing monomer unit in all the monomer units contained in the polymer A) is 20% by mass or more. It is preferably 25% by mass or more, more preferably 35% by mass or more, particularly preferably 60% by mass or less, more preferably 55% by mass or less, 53 It is particularly preferable that the content is not more than mass%. By setting the content of the amide group-containing monomer unit in the polymer A to the above lower limit or more, defects on the coating surface are reduced, and an electrode or separator formed using the binder composition is provided. The cycle characteristics of the secondary battery can be further improved. On the other hand, by setting the content of the amide group-containing monomer unit in the polymer A to the above upper limit or less, the functional layer (electrode layer, adhesive layer, Alternatively, the peel strength of the porous membrane layer) can be improved.
［酸官能基含有単量体単位］
　酸官能基含有単量体単位を形成し得る酸官能基含有単量体としては、酸官能基を含有する単量体であればよく、例えば、カルボン酸基（カルボキシル基）を有する単量体、スルホン酸基を有する単量体、リン酸基を有する単量体、などが挙げられる。 [Acid functional group-containing monomer unit]
The acid functional group-containing monomer capable of forming the acid functional group-containing monomer unit may be a monomer having an acid functional group, for example, a monomer having a carboxylic acid group (carboxyl group). , A monomer having a sulfonic acid group, a monomer having a phosphoric acid group, and the like.
　カルボン酸基を有する単量体としては、例えば、モノカルボン酸、ジカルボン酸、およびこれらの塩（ナトリウム塩、リチウム塩など）が挙げられる。モノカルボン酸としては、例えば、アクリル酸、メタクリル酸、クロトン酸が挙げられる。ジカルボン酸としては、例えば、マレイン酸、フマル酸、イタコン酸が挙げられる。
　スルホン酸基を有する単量体としては、例えば、スチレンスルホン酸、ビニルスルホン酸、メチルビニルスルホン酸、（メタ）アリルスルホン酸、（メタ）アクリル酸－２－スルホン酸エチル、２－アクリルアミド－２－メチルプロパンスルホン酸、３－アリロキシ－２－ヒドロキシプロパンスルホン酸、およびこれらの塩（リチウム塩、ナトリウム塩など）が挙げられる。
　なお、本発明において、「（メタ）アリル」とは、アリルおよび／またはメタリルを意味し、「（メタ）アクリル」とは、アクリルおよび／メタクリルを意味する。
　リン酸基を有する単量体としては、例えば、リン酸－２－（メタ）アクリロイルオキシエチル、リン酸メチル－２－（メタ）アクリロイルオキシエチル、リン酸エチル－（メタ）アクリロイルオキシエチル、およびこれらの塩（ナトリウム塩、リチウム塩など）が挙げられる。
　なお、本発明において、「（メタ）アクリロイル」とは、アクリロイルおよび／またはメタクリロイルを意味する。 Examples of the monomer having a carboxylic acid group include monocarboxylic acid, dicarboxylic acid, and salts thereof (sodium salt, lithium salt, etc.). Examples of the monocarboxylic acid include acrylic acid, methacrylic acid, and crotonic acid. Examples of the dicarboxylic acid include maleic acid, fumaric acid, and itaconic acid.
Examples of the monomer having a sulfonic acid group include styrene sulfonic acid, vinyl sulfonic acid, methyl vinyl sulfonic acid, (meth) allyl sulfonic acid, ethyl (meth) acrylic acid-2-sulfonate, 2-acrylamido-2 -Methylpropanesulfonic acid, 3-allyloxy-2-hydroxypropanesulfonic acid, and salts thereof (lithium salt, sodium salt, etc.).
In addition, in this invention, "(meth) allyl" means allyl and / or methallyl, and "(meth) acryl" means acryl and / or methacryl.
Examples of the monomer having a phosphoric acid group include 2- (meth) acryloyloxyethyl phosphate, methyl-2- (meth) acryloyloxyethyl phosphate, ethyl- (meth) acryloyloxyethyl phosphate, and These salts (sodium salt, lithium salt, etc.) are mentioned.
In addition, in this invention, "(meth) acryloyl" means acryloyl and / or methacryloyl.
　ここで、酸官能基含有単量体は、１種類を単独で用いてもよく、２種類以上を任意の比率で組み合わせて用いてもよい。これらの中でも、酸官能基含有単量体としては、カルボン酸基を有する単量体が好ましく、メタクリル酸、イタコン酸、アクリル酸、マレイン酸がより好ましく、重合体Ａにおける共重合性の観点から、アクリル酸が更に好ましい。 Here, as the acid functional group-containing monomer, one type may be used alone, or two or more types may be used in combination at an arbitrary ratio. Among these, the acid functional group-containing monomer is preferably a monomer having a carboxylic acid group, more preferably methacrylic acid, itaconic acid, acrylic acid, maleic acid, from the viewpoint of copolymerizability in the polymer A. , Acrylic acid is more preferable.
　そして、重合体Ａ中における酸官能基含有単量体単位の含有量（重合体Ａに含まれる全単量体単位中に占める酸官能基含有単量体単位の割合）は、１０質量％以上であることが好ましく、１５質量％以上であることがより好ましく、１８質量％以上であることが特に好ましく、また、４５質量％以下であることが好ましく、４０質量％以下であることがより好ましく、３５質量％以下であることが特に好ましい。重合体Ａ中における酸官能基含有単量体単位の含有量を上記下限値以上とすることで、調製した二次電池用スラリー組成物を用いて形成した機能層（電極層、接着層または多孔膜層）のピール強度を向上させることができる。一方、重合体Ａ中における酸官能基含有単量体単位の含有量を上記上限値以下とすることで、増粘が抑制された二次電池用スラリー組成物を調製することができる。 The content of the acid functional group-containing monomer unit in the polymer A (the ratio of the acid functional group-containing monomer unit in all the monomer units contained in the polymer A) is 10% by mass or more. Is preferred, 15% by mass or more is more preferred, 18% by mass or more is particularly preferred, 45% by mass or less is preferred, and 40% by mass or less is more preferred. , 35 mass% or less is particularly preferable. By setting the content of the acid functional group-containing monomer unit in the polymer A to the above lower limit or more, the functional layer (electrode layer, adhesive layer or porous layer) formed by using the prepared slurry composition for a secondary battery is prepared. The peel strength of the film layer) can be improved. On the other hand, by adjusting the content of the acid functional group-containing monomer unit in the polymer A to the above upper limit value or less, it is possible to prepare a slurry composition for a secondary battery in which thickening is suppressed.
［一般式（１）で表される単量体単位］
　一般式（１）で表される単量体単位を形成し得る単量体としては、例えば、酢酸ビニル、プロピオン酸ビニル、酪酸ビニル、イソ酪酸ビニル、吉草酸ビニル、イソ吉草酸ビニル、ヘキサン酸ビニル等の下記一般式（３）で表される単量体などが挙げられる。これらは、１種類を単独で用いてもよく、２種類以上を任意の比率で組み合わせて用いてもよい。
　これらの中でも、けん化の観点から、酢酸ビニル、プロピオン酸ビニル、酪酸ビニル、イソ酪酸ビニルが好ましく、酢酸ビニル、プロピオン酸ビニルがより好ましい。
Figure JPOXMLDOC01-appb-C000009
 （一般式（３）中、Ｒ1は、化学的な単結合、メチレン基、エチレン基、１，２－プロピレン基、または１，３－プロピレン基を表し、Ｒ4は、炭素数１～５のアルキル基を表す。）
　Ｒ1は、化学的な単結合、メチレン基、エチレン基、１，２－プロピレン基、および１，３－プロピレン基のいずれであってもよいが、後述する共重合体同士の架橋による得られる架橋体の自由度が小さい点で、化学的な単結合が好ましい。
　Ｒ4の炭素数１～５のアルキル基の具体例としては、例えば、メチル基、エチル基、プロピル基、イソプロピル基、ｎ－ブチル基、ｓｅｃ－ブチル基、イソブチル基、ｔｅｒｔ－ブチル基、ｎ－ペンチル基、イソペンチル基、ネオペンチル基、ｓｅｃ－ペンチル基、ｔｅｒｔ－ペンチル基が挙げられる。これらの中でも、けん化の観点から、メチル基、エチル基、プロピル基、イソプロピル基が好ましく、メチル基、エチル基がより好ましい。 [Monomer Unit Represented by General Formula (1)]
Examples of the monomer capable of forming the monomer unit represented by the general formula (1) include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl valerate, vinyl isovalerate, and hexanoic acid. Examples include monomers represented by the following general formula (3) such as vinyl. These may be used individually by 1 type and may be used in combination of 2 or more types by arbitrary ratios.
Among these, vinyl acetate, vinyl propionate, vinyl butyrate, and vinyl isobutyrate are preferable from the viewpoint of saponification, and vinyl acetate and vinyl propionate are more preferable.
Figure JPOXMLDOC01-appb-C000009
 (In the general formula (3), R 1 represents a chemical single bond, a methylene group, an ethylene group, a 1,2-propylene group or a 1,3-propylene group, and R 4 represents a carbon number of 1 to 5 Represents the alkyl group of.)
R 1 may be any of a chemical single bond, a methylene group, an ethylene group, a 1,2-propylene group, and a 1,3-propylene group, and is obtained by crosslinking the copolymers described below. A chemical single bond is preferable because the degree of freedom of the crosslinked body is small.
Specific examples of the alkyl group having 1 to 5 carbon atoms for R 4 include, for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group, tert-butyl group, n —Pentyl group, isopentyl group, neopentyl group, sec-pentyl group, tert-pentyl group. Among these, from the viewpoint of saponification, a methyl group, an ethyl group, a propyl group and an isopropyl group are preferable, and a methyl group and an ethyl group are more preferable.
　そして、重合体Ａ中における上記一般式（１）で表される単量体単位の含有量（重合体Ａに含まれる全単量体単位中に占める上記一般式（１）で表される単量体単位の割合）は、５質量％以上であることが好ましく、２０質量％以上であることがより好ましく、２５質量％以上であることが特に好ましく、４０質量％以下であることが好ましく、３５質量％以下であることがより好ましい。重合体Ａ中における上記一般式（１）で表される単量体単位の含有量を上記下限値以上とすることで、架橋性部位を増やして、バインダー組成物を用いて形成される電極またはセパレータを備える二次電池のサイクル特性をより向上させることができる。一方、重合体Ａ中における上記一般式（１）で表される単量体単位の含有量を上記上限値以下とすることで、塗工表面での欠陥を低減して、バインダー組成物を用いて形成される電極またはセパレータを備える二次電池のサイクル特性をより向上させることができる。 The content of the monomer unit represented by the general formula (1) in the polymer A (the unit represented by the general formula (1) in all the monomer units contained in the polymer A is The proportion of the monomer unit) is preferably 5% by mass or more, more preferably 20% by mass or more, particularly preferably 25% by mass or more, and preferably 40% by mass or less, It is more preferably 35% by mass or less. By setting the content of the monomer unit represented by the general formula (1) in the polymer A to the above lower limit or more, the number of crosslinkable sites is increased, and an electrode formed using the binder composition or It is possible to further improve the cycle characteristics of the secondary battery including the separator. On the other hand, when the content of the monomer unit represented by the general formula (1) in the polymer A is not more than the above upper limit, defects on the coated surface are reduced, and the binder composition is used. The cycle characteristics of the secondary battery including the electrode or the separator formed as described above can be further improved.
［その他の単量体単位］
　アミド基含有単量体単位、酸官能基含有単量体単位および一般式（１）で表される単量体単位以外の単量体単位としては、特に限定されないが、例えば、カルボン酸エステル単量体単位、芳香族単量体単位、脂肪族共役ジエン単量体単位が挙げられる。なお、その他の単量体単位は、１種類を単独で用いてもよく、２種類以上を任意の比率で組み合わせて用いてもよい。
　そして、重合体Ａ中におけるその他の単量体単位の含有量（重合体Ａに含まれる全単量体単位中に占めるその他の単量体単位の割合）は、０質量％以上であり、１０質量％以下であることが好ましい。 [Other monomer units]
The monomer unit other than the amide group-containing monomer unit, the acid functional group-containing monomer unit and the monomer unit represented by the general formula (1) is not particularly limited, and examples thereof include carboxylic acid ester monomer units. Examples thereof include a monomer unit, an aromatic monomer unit, and an aliphatic conjugated diene monomer unit. The other monomer units may be used alone or in combination of two or more kinds at any ratio.
The content of the other monomer units in the polymer A (ratio of the other monomer units in all the monomer units contained in the polymer A) is 0% by mass or more and 10 It is preferably not more than mass%.
［カルボン酸エステル単量体単位］
　カルボン酸エステル単量体単位を形成し得るカルボン酸エステル単量体としては、ヒドロキシメチルアクリレート、ヒドロキシエチルアクリレート、ヒドロキシプロピルアクリレート、ヒドロキシブチルアクリレート、ヒドロキシメチルメタクリレート、ヒドロキシエチルメタクリレート、ヒドロキシプロピルメタクリレート、ヒドロキシブチルメタクリレート、メチル（メタ）アクリレート、エチル（メタ）アクリレート、プロピル（メタ）アクリレート、ブチル（メタ）アクリレート、ペンチル（メタ）アクリレート、へキシル（メタ）アクリレート、へプチル（メタ）アクリレート、オクチル（メタ）アクリレート、２－エチルへキシル（メタ）アクリレート、ノナニル（メタ）アクリレート、アリル（メタ）アクリレート、などが挙げられる。これらは、１種類を単独で用いてもよく、２種類以上を任意の比率で組み合わせて用いてもよい。そしてこれらの中でも、重合安定性や電極真空乾燥時の熱架橋性の観点から、ヒドロキシエチルアクリレートが好ましい。
　なお、本発明において、「（メタ）アクリレート」とは、アクリレートおよび／メタクリレートを意味する。
　また、芳香族単量体単位を形成し得る芳香族単量体、脂肪族共役ジエン単量体単位を形成し得る脂肪族共役ジエン単量体としては、それぞれ「重合体Ｂ」の項で後述するものと同様のものを使用することができる。 [Carboxylic acid ester monomer unit]
Examples of the carboxylic acid ester monomer capable of forming the carboxylic acid ester monomer unit include hydroxymethyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxymethyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate and hydroxybutyl. Methacrylate, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) Acrylate, 2-ethylhexyl (meth) acrylate, nonanyl (meth) acrylate, allyl (meth) acrylate, etc. It is. These may be used individually by 1 type and may be used in combination of 2 or more types by arbitrary ratios. Of these, hydroxyethyl acrylate is preferable from the viewpoint of polymerization stability and thermal crosslinkability during electrode vacuum drying.
In addition, in this invention, "(meth) acrylate" means an acrylate and / methacrylate.
The aromatic monomer capable of forming an aromatic monomer unit and the aliphatic conjugated diene monomer capable of forming an aliphatic conjugated diene monomer unit will be described later in the section "Polymer B". It is possible to use the same one as that.
［重合体Ａの調製方法］
　重合体Ａは、上述した単量体を含む単量体組成物を、例えば水などの水系溶媒中で重合して共重合体を得て、得られた共重合体をけん化することにより、製造し得る。この際、単量体組成物中の各単量体の含有割合は、重合体Ａ中の各繰り返し単位（単量体単位）の含有量（含有割合）に準じて定めることができる。
　そして、重合様式は、特に制限なく、溶液重合法、懸濁重合法、塊状重合法、乳化重合法などのいずれの方法も用いることができる。また、重合反応としては、イオン重合、ラジカル重合、リビングラジカル重合などいずれの反応も用いることができる。
　また、重合に使用される乳化剤、分散剤、重合開始剤、重合助剤などの添加剤は、一般に用いられるものを使用しうる。これらの添加剤の使用量も、一般に使用される量としうる。重合条件は、重合方法および重合開始剤の種類などに応じて適宜調整しうる。 [Preparation Method of Polymer A]
The polymer A is produced by polymerizing a monomer composition containing the above-mentioned monomer in an aqueous solvent such as water to obtain a copolymer, and saponifying the obtained copolymer. You can At this time, the content ratio of each monomer in the monomer composition can be determined according to the content (content ratio) of each repeating unit (monomer unit) in the polymer A.
The polymerization mode is not particularly limited, and any method such as a solution polymerization method, a suspension polymerization method, a bulk polymerization method and an emulsion polymerization method can be used. As the polymerization reaction, any reaction such as ionic polymerization, radical polymerization and living radical polymerization can be used.
Further, as the additives such as an emulsifier, a dispersant, a polymerization initiator and a polymerization aid used for the polymerization, those generally used can be used. The amount of these additives used may be a commonly used amount. The polymerization conditions can be appropriately adjusted depending on the polymerization method and the type of polymerization initiator.
　上記共重合体のけん化により、下記反応式で示されるように、「－Ｒ1－Ｏ－Ｃ（＝Ｏ）－Ｒ4」が、「－Ｒ1－ＯＨ」となる。
　けん化のアルカリ処理に用いる試薬は、けん化効率および得られる二次電池特性の観点から、水酸化リチウム、水酸化ナトリウム、水酸化カリウムが好ましく、水酸化リチウムがより好ましい。 By saponification of the above copolymer, “—R 1 —O—C (═O) —R 4 ” becomes “—R 1 —OH” as shown in the following reaction formula.
From the viewpoint of saponification efficiency and the secondary battery characteristics obtained, the reagent used for the saponification alkali treatment is preferably lithium hydroxide, sodium hydroxide or potassium hydroxide, and more preferably lithium hydroxide.
　けん化のアルカリ処理における反応温度は、７０℃以上であることが好ましく、８０℃以上であることがより好ましく、９０℃以上であることが特に好ましく、１００℃以下であることが好ましく、９８℃以下であることがより好ましく、９６℃以下であることが特に好ましい。けん化のアルカリ処理における温度を上記下限値以上とすることで、より短時間でけん化度を上げることができる。一方、けん化のアルカリ処理における温度を上記上限値以下とすることで、分子鎖の切断が起こりにくくすることができる。 The reaction temperature in the alkali treatment for saponification is preferably 70 ° C or higher, more preferably 80 ° C or higher, particularly preferably 90 ° C or higher, preferably 100 ° C or lower, and 98 ° C or lower. Is more preferable, and it is particularly preferable that the temperature is 96 ° C. or lower. By setting the temperature in the alkali treatment for saponification to the above lower limit or more, the degree of saponification can be increased in a shorter time. On the other hand, by setting the temperature in the alkali treatment for saponification to the upper limit value or less, it is possible to prevent the molecular chain from breaking.
　けん化のアルカリ処理における反応時間は、５分間以上であることが好ましく、１０分間以上であることがより好ましく、１５分間以上であることが特に好ましく、３６０分間以下であることが好ましく、３００分間以下であることがより好ましく、２４０分間以下であることが特に好ましい。けん化のアルカリ処理における反応時間を上記下限値以上とすることで、目標のけん化度を達成することができる。一方、けん化のアルカリ処理における反応時間を上記上限値以下とすることで、分子鎖の切断が起こりにくくすることができる。 The reaction time in the alkali treatment for saponification is preferably 5 minutes or longer, more preferably 10 minutes or longer, particularly preferably 15 minutes or longer, more preferably 360 minutes or shorter, and 300 minutes or shorter. Is more preferable and 240 minutes or less is particularly preferable. The target degree of saponification can be achieved by setting the reaction time in the alkali treatment of saponification to the above lower limit or more. On the other hand, by setting the reaction time in the alkali treatment for saponification to the above upper limit value or less, it is possible to prevent the molecular chain from breaking.
　けん化度は、５０モル％以上であることが好ましく、９０モル％以上であることがより好ましく、９８モル％以上であることが特に好ましい。けん化度を上記下限値以上とすることで、サイクル特性を向上することができる。
Figure JPOXMLDOC01-appb-C000010
 The degree of saponification is preferably 50 mol% or more, more preferably 90 mol% or more, and particularly preferably 98 mol% or more. By setting the degree of saponification to be the above lower limit or more, cycle characteristics can be improved.
Figure JPOXMLDOC01-appb-C000010
　さらに、上記反応式で示されるように、けん化された共重合体における水酸基同士が脱水縮合することで、「－Ｒ1－Ｏ－Ｒ1－」の架橋部構造が得られる。なお、「－Ｒ1－Ｏ－Ｒ1－」における２つのＲ1は、同じであっても異なっていてもよい。
　このように、けん化された共重合体における水酸基同士が脱水縮合して共重合体同士が架橋することで、例えば、後述する金属系負極活物質としてのシリコン系負極活物質の体積膨張に基づく導電パス切断に起因する二次電池性能の劣化を防止することができる。
　また、けん化された共重合体の架橋部構造（－Ｒ1－Ｏ－Ｒ1－）の炭素数が最大でも６であるので（Ｒ1の炭素数が最大でも３）、架橋部構造（－Ｒ1－Ｏ－Ｒ1－）の長さが比較的短く、共重合体の分子鎖の自由度が小さい。
　なお、けん化された共重合体における水酸基同士の脱水縮合は、スラリー組成物の真空乾燥、および／または電極層形成後の真空乾燥等により行われる。
　真空乾燥の条件としては、例えば、乾燥温度が５０℃以上２００℃以下であり、乾燥時間が３６０分間以上１２００分間以下である。 Further, as shown in the above reaction formula, dehydration condensation between the hydroxyl groups in the saponified copolymer gives a cross-linking part structure of "-R 1 -O-R 1- ". The two R 1 's in "-R 1 -O-R 1- " may be the same or different.
In this way, the hydroxyl groups in the saponified copolymer are dehydrated and condensed to cross-link the copolymers, and, for example, the conductivity based on the volume expansion of the silicon-based negative electrode active material as the metal-based negative electrode active material described later is obtained. It is possible to prevent the deterioration of the performance of the secondary battery due to the disconnection of the path.
Further, since the number of carbon atoms in the crosslinked portion structure (-R 1 -OR 1- ) of the saponified copolymer is at most 6 (the maximum number of carbon atoms in R 1 is 3), the crosslinked portion structure (- The length of R 1 —O—R 1 —) is relatively short, and the degree of freedom of the molecular chain of the copolymer is small.
The dehydration condensation of the hydroxyl groups in the saponified copolymer is performed by vacuum drying the slurry composition and / or vacuum drying after forming the electrode layer.
The conditions for vacuum drying are, for example, a drying temperature of 50 ° C. or higher and 200 ° C. or lower, and a drying time of 360 minutes or longer and 1200 minutes or shorter.
［重合体Ａの性状］
　重合体Ａの重量平均分子量は、１００万以上であることが好ましく、２００万以上であることがより好ましく、５００万以上であることが特に好ましく、また、１０００万以下であることが好ましく、８００万以下であることがより好ましく、７００万以下であることが特に好ましい。重合体Ａの重量平均分子量を上記下限値以上とすることで、バインダー組成物を用いて形成される機能層（電極層または多孔膜層）のバルク強度を向上させて、ピール強度を向上させることができる。一方、重合体Ａの重量平均分子量を上記上限値以下とすることで、増粘が抑制された二次電池用スラリー組成物を調製することができることができる。 [Properties of Polymer A]
The weight average molecular weight of the polymer A is preferably 1,000,000 or more, more preferably 2,000,000 or more, particularly preferably 5,000,000 or more, and preferably 10,000,000 or less, 800 It is more preferably 10,000 or less, and particularly preferably 7 million or less. By increasing the weight average molecular weight of the polymer A to the above lower limit or more, the bulk strength of the functional layer (electrode layer or porous membrane layer) formed using the binder composition is improved, and the peel strength is improved. You can On the other hand, by setting the weight average molecular weight of the polymer A to be equal to or less than the above upper limit value, it is possible to prepare a slurry composition for a secondary battery in which viscosity increase is suppressed.
　重合体Ａの電解液膨潤度は、１００質量％以上であることが好ましく、また、１５０質量％以下であることが好ましく、１４５質量％以下であることがより好ましく、１３５質量％以下であることが特に好ましい。重合体Ａの電解液膨潤度を上記上限値以下とすることで、得られる二次電池のサイクル特性をより向上させることができる。 The electrolyte solution swelling degree of the polymer A is preferably 100% by mass or more, more preferably 150% by mass or less, more preferably 145% by mass or less, and 135% by mass or less. Is particularly preferable. By setting the electrolytic solution swelling degree of the polymer A to be equal to or less than the above upper limit value, the cycle characteristics of the obtained secondary battery can be further improved.
＜重合体Ｂ＞
　重合体Ｂは、脂肪族共役ジエン単量体単位および芳香族単量体単位の少なくともいずれかを含み、好ましくは、脂肪族共役ジエン単量体単位および芳香族単量体単位の双方を含む。なお、重合体Ｂは、任意に、脂肪族共役ジエン単量体単位および芳香族単量体単位以外の単量体単位を含んでいてもよい。重合体Ｂがこのような単量体組成を有することで、二次電池用スラリー組成物の増粘を抑制することができる。また、重合体Ｂは、水溶解型でなく、水分散体型である。 <Polymer B>
The polymer B contains at least one of an aliphatic conjugated diene monomer unit and an aromatic monomer unit, and preferably contains both an aliphatic conjugated diene monomer unit and an aromatic monomer unit. The polymer B may optionally contain a monomer unit other than the aliphatic conjugated diene monomer unit and the aromatic monomer unit. When the polymer B has such a monomer composition, it is possible to suppress the thickening of the slurry composition for a secondary battery. Further, the polymer B is not a water-soluble type but an aqueous dispersion type.
［脂肪族共役ジエン単量体単位］
　脂肪族共役ジエン単量体単位を形成し得る脂肪族共役ジエン単量体としては、特に限定されることなく、１，３－ブタジエン、２－メチル－１，３－ブタジエン（イソプレン）、２，３－ジメチル－１，３－ブタジエンなどが挙げられる。中でも、脂肪族共役ジエン単量体としては、１，３－ブタジエンおよびイソプレンが好ましく、架橋密度や架橋点間距離の観点から、１，３－ブタジエンがより好ましい。なお、脂肪族共役ジエン単量体は、１種類を単独で用いてもよく、２種類以上を任意の比率で組み合わせて用いてもよい。 [Aliphatic conjugated diene monomer unit]
The aliphatic conjugated diene monomer capable of forming the aliphatic conjugated diene monomer unit is not particularly limited, and 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2, Examples thereof include 3-dimethyl-1,3-butadiene. Among these, 1,3-butadiene and isoprene are preferable as the aliphatic conjugated diene monomer, and 1,3-butadiene is more preferable from the viewpoint of crosslinking density and distance between crosslinking points. The aliphatic conjugated diene monomer may be used alone or in combination of two or more kinds at an arbitrary ratio.
　そして、重合体Ｂ中における脂肪族共役ジエン単量体単位の含有量（重合体Ｂに含まれる全単量体単位中に占める脂肪族共役ジエン単量体単位の割合）は、１０質量％以上であることが好ましく、１５質量％以上であることがより好ましく、２０質量％以上であることが特に好ましく、また、９０質量％以下であることが好ましく、８５質量％以下であることがより好ましく、８０質量％以下であることが特に好ましい。重合体Ｂ中における脂肪族共役ジエン単量体単位の含有量を上記下限値以上とすることで、電極の柔軟性を向上させ、脆性破壊を抑制し、ピール強度を向上させることができる。一方、重合体Ｂ中における脂肪族共役ジエン単量体単位の含有量を上記上限値以下とすることで、電極膨れの劣化を抑制し、サイクル特性の低下を抑制することができる。 The content of the aliphatic conjugated diene monomer unit in the polymer B (the ratio of the aliphatic conjugated diene monomer unit in all the monomer units contained in the polymer B) is 10% by mass or more. Is preferable, 15% by mass or more is more preferable, 20% by mass or more is particularly preferable, 90% by mass or less is preferable, and 85% by mass or less is more preferable. Is particularly preferably 80% by mass or less. By setting the content of the aliphatic conjugated diene monomer unit in the polymer B to be the above lower limit or more, the flexibility of the electrode can be improved, brittle fracture can be suppressed, and the peel strength can be improved. On the other hand, by setting the content of the aliphatic conjugated diene monomer unit in the polymer B to be the above upper limit or less, deterioration of electrode swelling can be suppressed and deterioration of cycle characteristics can be suppressed.
［芳香族単量体単位］
　芳香族単量体単位を形成し得る芳香族単量体としては、特に限定されることなく、スチレン、スチレンスルホン酸およびその塩、α－メチルスチレン、ブトキシスチレン、ビニルナフタレン、等の芳香族ビニル単量体、などが挙げられる。中でも、芳香族単量体としては、機能層や電極層の接着強度の観点から、スチレンが好ましい。なお、芳香族単量体は、１種類を単独で用いてもよく、２種類以上を任意の比率で組み合わせて用いてもよい。 [Aromatic monomer unit]
The aromatic monomer capable of forming the aromatic monomer unit is not particularly limited, and aromatic vinyl such as styrene, styrenesulfonic acid and its salts, α-methylstyrene, butoxystyrene, vinylnaphthalene, etc. Examples thereof include monomers. Of these, styrene is preferable as the aromatic monomer from the viewpoint of the adhesive strength of the functional layer and the electrode layer. The aromatic monomers may be used alone or in combination of two or more at an arbitrary ratio.
　そして、重合体Ｂ中における芳香族単量体単位の含有量（重合体Ｂに含まれる全単量体単位中に占める芳香族単量体単位の割合）は、１０質量％以上であることが好ましく、１５質量％以上であることがより好ましく、２０質量％以上であることが特に好ましく、また、９０質量％以下であることが好ましく、８５質量％以下であることがより好ましく、８０質量％以下であることが特に好ましい。重合体Ｂ中における芳香族単量体単位の含有量を上記下限値以上とすることで、電極膨れの劣化を抑制し、サイクル特性の低下を抑制することができる。一方、重合体Ｂ中における芳香族単量体単位の含有量を上記上限値以下とすることで、電極の柔軟性を向上させ、脆性破壊を抑制し、ピール強度を向上させることができる。 The content of the aromatic monomer unit in the polymer B (the ratio of the aromatic monomer unit in all the monomer units contained in the polymer B) is 10% by mass or more. It is preferably 15% by mass or more, particularly preferably 20% by mass or more, preferably 90% by mass or less, more preferably 85% by mass or less, and 80% by mass. The following is particularly preferable. When the content of the aromatic monomer unit in the polymer B is at least the above lower limit value, deterioration of electrode swelling can be suppressed and deterioration of cycle characteristics can be suppressed. On the other hand, by setting the content of the aromatic monomer unit in the polymer B to be not more than the above upper limit value, the flexibility of the electrode can be improved, brittle fracture can be suppressed, and the peel strength can be improved.
［その他の単量体単位］
　脂肪族共役ジエン単量体単位および芳香族単量体単位以外の単量体単位としては、特に限定されないが、例えば、カルボン酸エステル単量体単位、カルボン酸基含有単量体単位が挙げられる。なお、その他の単量体単位は、１種類を単独で用いてもよく、２種類以上を任意の比率で組み合わせて用いてもよい。
　そして、重合体Ｂ中におけるその他の単量体単位の含有量（重合体Ｂに含まれる全単量体単位中に占めるその他の単量体単位の割合）は、０質量％以上であり、７質量％以下であることが好ましい。 [Other monomer units]
The monomer unit other than the aliphatic conjugated diene monomer unit and the aromatic monomer unit is not particularly limited, and examples thereof include a carboxylic acid ester monomer unit and a carboxylic acid group-containing monomer unit. .. The other monomer units may be used alone or in combination of two or more kinds at any ratio.
The content of the other monomer units in the polymer B (the ratio of the other monomer units in all the monomer units contained in the polymer B) is 0% by mass or more, and 7 It is preferably not more than mass%.
［カルボン酸エステル単量体単位］
　カルボン酸エステル単量体単位を形成し得るカルボン酸エステル単量体としては、ヒドロキシメチルアクリレート、ヒドロキシエチルアクリレート、ヒドロキシプロピルアクリレート、ヒドロキシブチルアクリレート、ヒドロキシメチルメタクリレート、ヒドロキシエチルメタクリレート、ヒドロキシプロピルメタクリレート、ヒドロキシブチルメタクリレート、メチル（メタ）アクリレート、エチル（メタ）アクリレート、プロピル（メタ）アクリレート、ブチル（メタ）アクリレート、ペンチル（メタ）アクリレート、へキシル（メタ）アクリレート、へプチル（メタ）アクリレート、オクチル（メタ）アクリレート、２－エチルへキシル（メタ）アクリレート、ノナニル（メタ）アクリレート、アリル（メタ）アクリレート、などが挙げられる。これらは、１種類を単独で用いてもよく、２種類以上を任意の比率で組み合わせて用いてもよい。
　これらの中でも、重合安定性の観点から、メチル（メタ）アクリレート、ブチル（メタ）アクリレート、ヒドロキシエチルアクリレート、アリル（メタ）アクリレートが好ましい。 [Carboxylic acid ester monomer unit]
Examples of the carboxylic acid ester monomer capable of forming the carboxylic acid ester monomer unit include hydroxymethyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxymethyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate and hydroxybutyl. Methacrylate, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) Acrylate, 2-ethylhexyl (meth) acrylate, nonanyl (meth) acrylate, allyl (meth) acrylate, etc. It is. These may be used individually by 1 type and may be used in combination of 2 or more types by arbitrary ratios.
Among these, methyl (meth) acrylate, butyl (meth) acrylate, hydroxyethyl acrylate, and allyl (meth) acrylate are preferable from the viewpoint of polymerization stability.
［カルボン酸基含有単量体単位］
　カルボン酸基含有単量体単位を形成し得るカルボン酸基含有単量体としては、メタクリル酸、アクリル酸、マレイン酸、イタコン酸、などが挙げられる。これらは、１種類を単独で用いてもよく、２種類以上を任意の比率で組み合わせて用いてもよい。
　これらの中でも、重合安定性の観点から、メタクリル酸が好ましい。 [Carboxylic acid group-containing monomer unit]
Examples of the carboxylic acid group-containing monomer capable of forming the carboxylic acid group-containing monomer unit include methacrylic acid, acrylic acid, maleic acid, and itaconic acid. These may be used individually by 1 type and may be used in combination of 2 or more types by arbitrary ratios.
Among these, methacrylic acid is preferable from the viewpoint of polymerization stability.
＜化合物Ｘ＞
　化合物Ｘは、下記一般式（２）で表される化合物である。そして化合物Ｘとしては、例えば、酢酸、酪酸、イソ酪酸、吉草酸、イソ吉草酸、ヘキサン酸、酢酸リチウム、酢酸ナトリウム、酢酸カリウム、酪酸リチウム、酪酸ナトリウム、酪酸カリウム、イソ酪酸リチウム、イソ酪酸ナトリウム、イソ酪酸カリウム、吉草酸リチウム、吉草酸ナトリウム、吉草酸カリウム、イソ吉草酸リチウム、イソ吉草酸ナトリウム、イソ吉草酸カリウム、ヘキサン酸リチウム、ヘキサン酸ナトリウム、ヘキサン酸カリウム、などが挙げられる。これらは、１種類を単独で用いてもよく、２種類以上を任意の比率で組み合わせて用いてもよい。
　これらの中でも、けん化効率および得られる二次電池特性の観点から、酢酸リチウムが好ましい。
Figure JPOXMLDOC01-appb-C000011
 （一般式（２）中、Ｘは、水素原子またはアルカリ金属原子を表し、Ｒ4は、前記と同じ意味を表し、その好適例も前記と同じである。） <Compound X>
The compound X is a compound represented by the following general formula (2). Examples of the compound X include acetic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, hexanoic acid, lithium acetate, sodium acetate, potassium acetate, lithium butyrate, sodium butyrate, potassium butyrate, lithium isobutyrate, and sodium isobutyrate. , Potassium isobutyrate, lithium valerate, sodium valerate, potassium valerate, lithium isovalerate, sodium isovalerate, potassium isovalerate, lithium hexanoate, sodium hexanoate, potassium hexanoate, and the like. These may be used individually by 1 type and may be used in combination of 2 or more types by arbitrary ratios.
Among these, lithium acetate is preferable from the viewpoints of saponification efficiency and obtained secondary battery characteristics.
Figure JPOXMLDOC01-appb-C000011
 (In the general formula (2), X represents a hydrogen atom or an alkali metal atom, R 4 has the same meaning as described above, and its preferred examples are also the same as those described above.)
　前記Ｘのアルカリ金属原子は、けん化効率および得られる二次電池特性の観点から、リチウム、ナトリウム、カリウムが好ましく、リチウムがより好ましい。 The alkali metal atom of X is preferably lithium, sodium or potassium, and more preferably lithium, from the viewpoint of saponification efficiency and secondary battery characteristics obtained.
　重合体Ａの固形分に対する化合物Ｘの含有割合は、１００質量ｐｐｍ以上であることが好ましく、２００質量ｐｐｍ以上であることがより好ましく、３００質量ｐｐｍ以上であることが特に好ましく、５０００００質量ｐｐｍ以下であることが好ましく、３０００質量ｐｐｍ以下であることがより好ましい。化合物Ｘの含有割合を上記下限値以上とすることで、二次電池用スラリー組成物が増粘するのを抑制することができる。一方、化合物Ｘの含有割合を上記上限値以下とすることで、リチウム金属が析出するのを抑制することができる。
　なお、二次電池用バインダー組成物に上記化合物Ｘを含有させる方法は特に限定されない。例えば、重合体Ａを調製するに際し、上述したけん化を用いる手法を採用することにより、重合体Ａと共に、カルボン酸（およびまたはその塩）である化合物Ｘを生成させて、重合体Ａおよび化合物Ｘを含むバインダー組成物を調製することができる。 The content ratio of the compound X with respect to the solid content of the polymer A is preferably 100 mass ppm or more, more preferably 200 mass ppm or more, particularly preferably 300 mass ppm or more, and 500000 mass ppm or less. Is preferable and 3000 mass ppm or less is more preferable. By setting the content ratio of the compound X to be the above lower limit value or more, it is possible to suppress the viscosity of the slurry composition for a secondary battery from increasing. On the other hand, by setting the content ratio of the compound X to be equal to or less than the above upper limit value, it is possible to suppress precipitation of lithium metal.
The method of incorporating the compound X into the binder composition for a secondary battery is not particularly limited. For example, when the polymer A is prepared, the method using saponification described above is employed to generate the compound X which is a carboxylic acid (and / or a salt thereof) together with the polymer A, and the polymer A and the compound X are then formed. A binder composition containing can be prepared.
＜溶媒＞
　本発明の二次電池用バインダー組成物が含有する溶媒としては、特に限定されることなく、水が挙げられる。なお、溶媒は、水溶液であってもよく、水と少量の有機溶媒との混合溶液であってもよい。 <Solvent>
The solvent contained in the binder composition for a secondary battery of the present invention is not particularly limited and may be water. The solvent may be an aqueous solution or a mixed solution of water and a small amount of organic solvent.
＜その他の成分＞
　本発明の二次電池用バインダー組成物は、上記成分の他に、防腐剤、補強材、レベリング剤、粘度調整剤、電解液添加剤等の成分を含有していてもよい。これらは、電池反応に影響を及ぼさないものであれば特に限られず、公知のもの、例えば国際公開第２０１２／１１５０９６号に記載のものを使用することができる。また、これらの成分は、１種類を単独で用いてもよく、２種類以上を任意の比率で組み合わせて用いてもよい。 <Other ingredients>
The binder composition for a secondary battery of the present invention may contain components such as a preservative, a reinforcing material, a leveling agent, a viscosity modifier, and an electrolyte solution additive, in addition to the above components. These are not particularly limited as long as they do not affect the battery reaction, and known ones such as those described in International Publication No. 2012/115096 can be used. Moreover, these components may be used individually by 1 type, and may be used in combination of 2 or more types in arbitrary ratios.
＜二次電池用バインダー組成物の調製＞
　本発明の二次電池用バインダー組成物の調製方法は、特に限定されないが、例えば、水溶解型の重合体（水溶性重合体）である重合体Ａの調製を水系媒体中で実施し、重合体Ａが水溶液として得られる場合には、重合体Ａの水溶液をそのまま二次電池用バインダー組成物としてもよいし、重合体Ａの水溶液に任意の重合体Ｂおよび／またはその他の成分を加えて二次電池用バインダー組成物としてもよい。 <Preparation of Binder Composition for Secondary Battery>
The method for preparing the binder composition for a secondary battery of the present invention is not particularly limited, but for example, the preparation of polymer A, which is a water-soluble polymer (water-soluble polymer), is carried out in an aqueous medium, When the polymer A is obtained as an aqueous solution, the aqueous solution of the polymer A may be used as it is as the binder composition for a secondary battery, or the polymer B and / or other components may be added to the aqueous solution of the polymer A. It may be a binder composition for a secondary battery.
（二次電池用バインダー組成物の製造方法）
　本発明の二次電池用バインダー組成物の製造方法は、上述した本発明の二次電池用バインダー組成物を製造する製造方法であって、少なくとも、共重合工程と、けん化工程とを含み、必要に応じて、任意のその他の工程を含む。
　なおここで、共重合工程は、アミド基含有単量体、酸官能基含有単量体、および上記一般式（３）で表される単量体を共重合して、共重合体を得る工程であり、けん化工程は、共重合体をけん化して、重合体Ａを得る工程である。
　なお、共重合およびけん化の条件等は、「重合体Ａの調製方法」の欄で上述した通りである。
　その他の工程としては、例えば、防腐剤を添加する工程、固形分濃度を調整する工程、などが挙げられる。 (Method for producing binder composition for secondary battery)
The method for producing a binder composition for a secondary battery of the present invention is a method for producing the binder composition for a secondary battery of the present invention described above, which includes at least a copolymerization step and a saponification step, and is required. And optionally other steps.
Here, the copolymerization step is a step of copolymerizing the amide group-containing monomer, the acid functional group-containing monomer, and the monomer represented by the general formula (3) to obtain a copolymer. The saponification step is a step of saponifying the copolymer to obtain the polymer A.
The conditions of copolymerization and saponification are as described above in the section "Method for preparing polymer A".
Examples of the other steps include a step of adding a preservative and a step of adjusting the solid content concentration.
（二次電池用スラリー組成物）
　本発明の二次電池用スラリー組成物は、少なくとも、本発明の二次電池用バインダー組成物を含み、さらに、非導電性微粒子または電極活物質、任意のその他の成分を含有する、水等を分散媒としたスラリー組成物である。
　また本発明の二次電池用スラリー組成物が非導電性微粒子を含む場合、本発明の二次電池用スラリー組成物を用いて得られる機能層は、耐熱性や強度に優れる多孔膜層として良好に機能することができる。
　また本発明の二次電池用スラリー組成物が電極活物質を含む場合、本発明の二次電池用スラリー組成物を用いて得られる機能層は、ピール強度に優れており、且つ、電極を用いた二次電池に優れたサイクル特性を発揮させることができる電極層として良好に機能することができる。 (Slurry composition for secondary battery)
The secondary battery slurry composition of the present invention includes at least the secondary battery binder composition of the present invention, further contains non-conductive fine particles or electrode active material, any other component, water, etc. It is a slurry composition used as a dispersion medium.
When the secondary battery slurry composition of the present invention contains non-conductive fine particles, the functional layer obtained by using the secondary battery slurry composition of the present invention is good as a porous film layer having excellent heat resistance and strength. Can function to.
When the secondary battery slurry composition of the present invention contains an electrode active material, the functional layer obtained by using the secondary battery slurry composition of the present invention has excellent peel strength and uses electrodes. The secondary battery can function well as an electrode layer capable of exhibiting excellent cycle characteristics.
＜電極活物質を含むスラリー組成物の全固形分質量に対する重合体Ａの質量の割合（重合体Ａの質量／電極活物質を含むスラリー組成物の全固形分質量）＞
　電極活物質を含むスラリー組成物の全固形分質量に対する重合体Ａの質量の割合（重合体Ａの質量／電極活物質を含むスラリー組成物の全固形分質量）としては、１．０質量％以上であることが好ましく、２．０質量％以上であることがより好ましく、また、７．０質量％以下であることが好ましく、５．０質量％以下であることがより好ましい。前記割合を上記下限値以上とすることで、スラリー組成物が電極活物質を含む場合において電極活物質の分散性が悪化するのを抑制して、得られる二次電池のサイクル特性が低下するのを抑制することができる。一方、前記割合を上記上限値以下とすることで、得られる二次電池のセル容量低下およびセル抵抗増大を抑制することができる。 <Ratio of Mass of Polymer A to Mass of Total Solid Content of Slurry Composition Containing Electrode Active Material (mass of Polymer A / mass of Total Solid Content of Slurry Composition Containing Electrode Active Material)>
The ratio of the mass of the polymer A to the mass of the total solid content of the slurry composition containing the electrode active material (mass of the polymer A / mass of the total solid content of the slurry composition containing the electrode active material) is 1.0 mass%. It is preferably at least 2.0 mass%, more preferably at least 2.0 mass%, preferably at most 7.0 mass%, more preferably at most 5.0 mass%. By setting the ratio to the above lower limit or more, it is possible to suppress deterioration of the dispersibility of the electrode active material in the case where the slurry composition contains the electrode active material, and to reduce the cycle characteristics of the obtained secondary battery. Can be suppressed. On the other hand, by setting the ratio to be equal to or less than the upper limit value, it is possible to suppress a decrease in cell capacity and an increase in cell resistance of the obtained secondary battery.
＜電極活物質を含むスラリー組成物の全固形分質量に対する重合体Ｂの質量の割合（電極活物質を含む重合体Ｂの質量／スラリー組成物の全固形分質量）＞
　電極活物質を含むスラリー組成物の全固形分質量に対する重合体Ｂの質量の割合（重合体Ｂの質量／電極活物質を含むスラリー組成物の全固形分質量）としては、０．２質量％以上であることが好ましく、０．５質量％以上であることがより好ましく、また、３．０質量％以下であることが好ましく、２．０質量％以下であることがより好ましい。前記割合を上記下限値以上とすることで、得られる電極層の接着強度を向上させることができ、ひいては電極のピール強度を向上させることができる。一方、前記割合を上記上限値以下とすることで、得られる二次電池のセル容量低下およびセル抵抗増大を防止することができる。 <Ratio of mass of polymer B to mass of total solid content of slurry composition containing electrode active material (mass of polymer B containing electrode active material / mass of total solid content of slurry composition)>
As a ratio of the mass of the polymer B to the mass of the total solid content of the slurry composition containing the electrode active material (mass of the polymer B / mass of the total solid content of the slurry composition containing the electrode active material), 0.2 mass% It is preferably at least 0.5% by mass, more preferably at least 0.5% by mass, and preferably at most 3.0% by mass, more preferably at most 2.0% by mass. By setting the above ratio to the above lower limit or more, the adhesive strength of the obtained electrode layer can be improved, and by extension, the peel strength of the electrode can be improved. On the other hand, by setting the above ratio to be equal to or less than the above upper limit, it is possible to prevent a decrease in cell capacity and an increase in cell resistance of the obtained secondary battery.
＜非導電性微粒子を含むスラリー組成物の全固形分質量に対する重合体Ａの質量の割合（重合体Ａの質量／非導電性微粒子を含むスラリー組成物の全固形分質量）＞
　非導電性微粒子を含むスラリー組成物の全固形分質量に対する重合体Ａの質量の割合（重合体Ａの質量／非導電性微粒子を含むスラリー組成物の全固形分質量）としては、０．２質量％以上であることが好ましく、０．５質量％以上であることがより好ましく、また、７．０質量％以下であることが好ましく、４．０質量％以下であることがより好ましい。前記割合を上記下限値以上とすることで、強度に優れる多孔膜層を形成することができる。一方、前記割合を上記上限値以下とすることで、耐熱性に優れる多孔膜層を形成することができる。 <Ratio of the mass of the polymer A to the total solid mass of the slurry composition containing the non-conductive fine particles (mass of the polymer A / total solid mass of the slurry composition containing the non-conductive fine particles)>
The ratio of the mass of the polymer A to the total solid mass of the slurry composition containing the non-conductive fine particles (mass of the polymer A / total solid mass of the slurry composition containing the non-conductive fine particles) is 0.2. It is preferably at least mass%, more preferably at least 0.5 mass%, at most 7.0 mass%, and even more preferably at most 4.0 mass%. By setting the above ratio to the above lower limit or more, a porous membrane layer having excellent strength can be formed. On the other hand, by setting the above ratio to the above upper limit or less, it is possible to form a porous membrane layer having excellent heat resistance.
＜非導電性微粒子を含むスラリー組成物の全固形分質量に対する重合体Ｂの質量の割合（重合体Ｂの質量／非導電性微粒子を含むスラリー組成物の全固形分質量）＞
　非導電性微粒子を含むスラリー組成物の全固形分質量に対する重合体Ｂの質量の割合（重合体Ｂの質量／非導電性微粒子を含むスラリー組成物の全固形分質量）としては、０．２質量％以上であることが好ましく、０．５質量％以上であることがより好ましく、また、７．０質量％以下であることが好ましく、５．０質量％以下であることがより好ましい。前記割合を上記下限値以上とすることで、強度に優れる多孔膜層を形成することができる。一方、前記割合を上記上限値以下とすることで、耐熱性に優れる多孔膜層を形成することができる。 <Ratio of mass of polymer B to mass of total solid content of slurry composition containing non-conductive fine particles (mass of polymer B / mass of total solid content of slurry composition containing non-conductive fine particles)>
The ratio of the mass of the polymer B to the mass of the total solid content of the slurry composition containing the non-conductive fine particles (mass of the polymer B / mass of the total solid content of the slurry composition containing the non-conductive fine particles) is 0.2. It is preferably at least mass%, more preferably at least 0.5 mass%, preferably at most 7.0 mass%, more preferably at most 5.0 mass%. By setting the above ratio to the above lower limit or more, a porous membrane layer having excellent strength can be formed. On the other hand, by setting the above ratio to the above upper limit or less, it is possible to form a porous membrane layer having excellent heat resistance.
＜非導電性微粒子＞
　ここで、非導電性微粒子は、水等の分散媒および二次電池の非水系電解液に溶解せず、それらの中においても、その形状が維持される粒子である。そして、非導電性微粒子は、電気化学的にも安定であるため、二次電池の使用環境下で機能層中に安定に存在する。 <Non-conductive fine particles>
Here, the non-conductive fine particles are particles that do not dissolve in a dispersion medium such as water and the non-aqueous electrolyte solution of the secondary battery, and the shape thereof is maintained even in them. Since the non-conductive fine particles are electrochemically stable, they are stably present in the functional layer under the usage environment of the secondary battery.
　そして、非導電性微粒子としては、例えば各種の無機微粒子や有機微粒子を使用することができる。
　具体的には、非導電性微粒子としては、無機微粒子と、有機微粒子との双方を用いることができるが、通常は無機微粒子が用いられる。なかでも、非導電性微粒子の材料としては、二次電池の使用環境下で安定に存在し、電気化学的に安定である材料が好ましい。このような観点から非導電性微粒子の材料の好ましい例を挙げると、酸化アルミニウム（アルミナ）、水和アルミニウム酸化物（ベーマイト）、酸化ケイ素、酸化マグネシウム（マグネシア）、酸化カルシウム、酸化チタン（チタニア）、ＢａＴｉＯ3、ＺｒＯ、アルミナ－シリカ複合酸化物等の酸化物粒子；窒化アルミニウム、窒化ホウ素等の窒化物粒子；シリコン、ダイヤモンド等の共有結合性結晶粒子；硫酸バリウム、フッ化カルシウム、フッ化バリウム等の難溶性イオン結晶粒子；タルク、モンモリロナイト等の粘土微粒子；などが挙げられる。また、これらの粒子は必要に応じて元素置換、表面処理、固溶体化等が施されていてもよい。
　上述した非導電性微粒子は、１種類を単独で使用してもよいし、２種類以上を組み合わせて用いてもよい。そして非導電性微粒子としては、酸化アルミニウム（アルミナ）が好ましい。また非導電性微粒子の粒径は、特に限定されることなく、従来使用されている非導電性微粒子と同様とすることができる。 Then, as the non-conductive fine particles, for example, various kinds of inorganic fine particles and organic fine particles can be used.
Specifically, as the non-conductive fine particles, both inorganic fine particles and organic fine particles can be used, but the inorganic fine particles are usually used. Among them, the material of the non-conductive fine particles is preferably a material that stably exists in the usage environment of the secondary battery and is electrochemically stable. From this point of view, preferred examples of the material of the non-conductive fine particles include aluminum oxide (alumina), hydrated aluminum oxide (boehmite), silicon oxide, magnesium oxide (magnesia), calcium oxide, titanium oxide (titania). , BaTiO 3 , ZrO, oxide particles such as alumina-silica composite oxide; nitride particles such as aluminum nitride and boron nitride; covalent bond crystal particles such as silicon and diamond; barium sulfate, calcium fluoride, barium fluoride And the like, and slightly soluble ionic crystal particles such as talc and clay fine particles such as talc and montmorillonite. Further, these particles may be subjected to element substitution, surface treatment, solid solution treatment or the like, if necessary.
The above non-conductive fine particles may be used alone or in combination of two or more. Aluminum oxide (alumina) is preferable as the non-conductive fine particles. The particle size of the non-conductive fine particles is not particularly limited and may be the same as the conventionally used non-conductive fine particles.
＜スラリー組成物の全固形分質量に対する非導電性微粒子の質量の割合（非導電性微粒子の質量／スラリー組成物の全固形分質量）＞
　スラリー組成物の全固形分質量に対する非導電性微粒子の質量の割合（非導電性微粒子の質量／スラリー組成物の全固形分質量）としては、８５質量％以上であることが好ましく、８７量％以上であることがより好ましく、また、９９質量％以下であることが好ましく、９７質量％以下であることがより好ましい。前記割合を上記下限値以上とすることで、良好な耐熱性が得ることができる。一方、前記割合を上記上限値以下とすることで、多孔質膜に良好な密着強度を付与することができる。 <Ratio of mass of non-conductive fine particles to mass of total solid content of slurry composition (mass of non-conductive fine particles / mass of total solid content of slurry composition)>
The mass ratio of the non-conductive fine particles to the total solid mass of the slurry composition (mass of non-conductive fine particles / mass of the total solid content of the slurry composition) is preferably 85% by mass or more, and 87% by mass More preferably, it is more preferably 99% by mass or less, and more preferably 97% by mass or less. Good heat resistance can be obtained by setting the above ratio to the above lower limit or more. On the other hand, by setting the above ratio to the above upper limit or less, good adhesion strength can be imparted to the porous film.
＜電極活物質＞
　電極活物質は、二次電池の電極（正極、負極）において電子の受け渡しをする物質である。そして、例えばリチウムイオン二次電池の電極活物質（正極活物質、負極活物質）としては、通常は、リチウムを吸蔵および放出し得る物質を用いる。 <Electrode active material>
The electrode active material is a material that transfers electrons at the electrodes (positive electrode, negative electrode) of the secondary battery. Then, for example, as an electrode active material (positive electrode active material, negative electrode active material) of a lithium ion secondary battery, a material capable of inserting and extracting lithium is usually used.
［正極活物質］
　具体的には、正極活物質としては、遷移金属を含有する化合物、例えば、遷移金属酸化物、遷移金属硫化物、リチウムと遷移金属との複合金属酸化物などを用いることができる。なお、遷移金属としては、例えば、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｆｅ、Ｃｏ、Ｎｉ、Ｃｕ、Ｍｏ等が挙げられる。 [Cathode active material]
Specifically, a compound containing a transition metal, such as a transition metal oxide, a transition metal sulfide, or a composite metal oxide of lithium and a transition metal, can be used as the positive electrode active material. Examples of transition metals include Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Mo, and the like.
　ここで、遷移金属酸化物としては、例えばＭｎＯ、ＭｎＯ2、Ｖ2Ｏ5、Ｖ6Ｏ13、ＴｉＯ2、Ｃｕ2Ｖ2Ｏ3、非晶質Ｖ2Ｏ－Ｐ2Ｏ5、非晶質ＭｏＯ3、非晶質Ｖ2Ｏ5、非晶質Ｖ6Ｏ13等が挙げられる。
　遷移金属硫化物としては、ＴｉＳ2、ＴｉＳ3、非晶質ＭｏＳ2、ＦｅＳなどが挙げられる。
　リチウムと遷移金属との複合金属酸化物としては、層状構造を有するリチウム含有複合金属酸化物、スピネル型構造を有するリチウム含有複合金属酸化物、オリビン型構造を有するリチウム含有複合金属酸化物などが挙げられる。 Here, examples of the transition metal oxide include MnO, MnO 2 , V 2 O 5 , V 6 O 13 , TiO 2 , Cu 2 V 2 O 3 , amorphous V 2 O-P 2 O 5 , and amorphous. Quality MoO 3 , amorphous V 2 O 5 , amorphous V 6 O 13 and the like.
Examples of transition metal sulfides include TiS 2 , TiS 3 , amorphous MoS 2 , and FeS.
Examples of the composite metal oxide of lithium and a transition metal include a lithium-containing composite metal oxide having a layered structure, a lithium-containing composite metal oxide having a spinel structure, and a lithium-containing composite metal oxide having an olivine structure. Be done.
　層状構造を有するリチウム含有複合金属酸化物としては、例えば、リチウム含有コバルト酸化物（ＬｉＣｏＯ2）、リチウム含有ニッケル酸化物（ＬｉＮｉＯ2）、Ｃｏ－Ｎｉ－Ｍｎのリチウム含有複合酸化物（Ｌｉ（ＣｏＭｎＮｉ）Ｏ2）、Ｎｉ－Ｍｎ－Ａｌのリチウム含有複合酸化物、Ｎｉ－Ｃｏ－Ａｌのリチウム含有複合酸化物、ＬｉＭａＯ2とＬｉ2ＭｂＯ3との固溶体などが挙げられる。なお、Ｃｏ－Ｎｉ－Ｍｎのリチウム含有複合酸化物としては、Ｌｉ［Ｎｉ0.5Ｃｏ0.2Ｍｎ0.3］Ｏ2、Ｌｉ［Ｎｉ1/3Ｃｏ1/3Ｍｎ1/3］Ｏ2などが挙げられる。また、ＬｉＭａＯ2とＬｉ2ＭｂＯ3との固溶体としては、例えば、ｘＬｉＭａＯ2・（１－ｘ）Ｌｉ2ＭｂＯ3などが挙げられる。ここで、ｘは０＜ｘ＜１を満たす数を表し、Ｍａは平均酸化状態が３＋である１種類以上の遷移金属を表し、Ｍｂは平均酸化状態が４＋である１種類以上の遷移金属を表す。このような固溶体としては、Ｌｉ［Ｎｉ0.17Ｌｉ0.2Ｃｏ0.07Ｍｎ0.56］Ｏ2などが挙げられる。
　なお、本明細書において、「平均酸化状態」とは、前記「１種類以上の遷移金属」の平均の酸化状態を示し、遷移金属のモル量と原子価とから算出される。例えば、「１種類以上の遷移金属」が、５０ｍｏｌ％のＮｉ2+と５０ｍｏｌ％のＭｎ4+から構成される場合には、「１種類以上の遷移金属」の平均酸化状態は、（０．５）×（２＋）＋（０．５）×（４＋）＝３＋となる。 Examples of the lithium-containing composite metal oxide having a layered structure include lithium-containing cobalt oxide (LiCoO 2 ), lithium-containing nickel oxide (LiNiO 2 ), and Co—Ni—Mn lithium-containing composite oxide (Li (CoMnNi ) O 2 ), a lithium-containing composite oxide of Ni—Mn—Al, a lithium-containing composite oxide of Ni—Co—Al, a solid solution of LiMaO 2 and Li 2 MbO 3, and the like. Examples of the lithium-containing composite oxide of Co—Ni—Mn include Li [Ni 0.5 Co 0.2 Mn 0.3 ] O 2 and Li [Ni 1/3 Co 1/3 Mn 1/3 ] O 2 . Examples of the solid solution of LiMaO 2 and Li 2 MbO 3 include xLiMaO 2 · (1-x) Li 2 MbO 3 . Here, x represents a number satisfying 0 <x <1, Ma represents one or more kinds of transition metals having an average oxidation state of 3+, and Mb represents one or more kinds of transition metals having an average oxidation state of 4+. Represent Examples of such solid solution include Li [Ni 0.17 Li 0.2 Co 0.07 Mn 0.56 ] O 2 .
In the present specification, the “average oxidation state” refers to the average oxidation state of the “one or more kinds of transition metals” and is calculated from the molar amount of transition metal and the valence. For example, when the “one or more transition metals” is composed of 50 mol% Ni 2+ and 50 mol% Mn 4+ , the average oxidation state of the “one or more transition metals” is (0. 5) × (2 +) + (0.5) × (4 +) = 3+.
　スピネル型構造を有するリチウム含有複合金属酸化物としては、例えば、マンガン酸リチウム（ＬｉＭｎ2Ｏ4）や、マンガン酸リチウム（ＬｉＭｎ2Ｏ4）のＭｎの一部を他の遷移金属で置換した化合物が挙げられる。具体例としては、ＬｉＮｉ0.5Ｍｎ1.5Ｏ4などのＬｉs［Ｍｎ2-tＭｃt］Ｏ4が挙げられる。ここで、Ｍｃは平均酸化状態が４＋である１種類以上の遷移金属を表す。Ｍｃの具体例としては、Ｎｉ、Ｃｏ、Ｆｅ、Ｃｕ、Ｃｒ等が挙げられる。また、ｔは０＜ｔ＜１を満たす数を表し、ｓは０≦ｓ≦１を満たす数を表す。なお、正極活物質としては、Ｌｉ1+xＭｎ2-xＯ4（０＜Ｘ＜２）で表されるリチウム過剰のスピネル化合物なども用いることができる。 Examples of the lithium-containing mixed metal oxide having a spinel structure include lithium manganate (LiMn 2 O 4 ) and compounds obtained by substituting a part of Mn of lithium manganate (LiMn 2 O 4 ) with another transition metal. Is mentioned. Specific examples include Li s [Mn 2-t Mc t] O 4 , such as LiNi 0.5 Mn 1.5 O 4. Here, Mc represents one or more kinds of transition metals having an average oxidation state of 4+. Specific examples of Mc include Ni, Co, Fe, Cu, Cr and the like. Further, t represents a number satisfying 0 <t <1, and s represents a number satisfying 0 ≦ s ≦ 1. As the positive electrode active material, a lithium-excess spinel compound represented by Li 1 + x Mn 2-x O 4 (0 <X <2) can also be used.
　オリビン型構造を有するリチウム含有複合金属酸化物としては、例えば、オリビン型リン酸鉄リチウム（ＬｉＦｅＰＯ4）、オリビン型リン酸マンガンリチウム（ＬｉＭｎＰＯ4）などのＬｉyＭｄＰＯ4で表されるオリビン型リン酸リチウム化合物が挙げられる。ここで、Ｍｄは平均酸化状態が３＋である１種類以上の遷移金属を表し、例えばＭｎ、Ｆｅ、Ｃｏ等が挙げられる。また、ｙは０≦ｙ≦２を満たす数を表す。さらに、ＬｉyＭｄＰＯ4で表されるオリビン型リン酸リチウム化合物は、Ｍｄが他の金属で一部置換されていてもよい。置換しうる金属としては、例えば、Ｃｕ、Ｍｇ、Ｚｎ、Ｖ、Ｃａ、Ｓｒ、Ｂａ、Ｔｉ、Ａｌ、Ｓｉ、ＢおよびＭｏなどが挙げられる。 Examples of the lithium-containing composite metal oxide having an olivine type structure include olivine type phosphorus represented by Li y MdPO 4 such as olivine type lithium iron phosphate (LiFePO 4 ) and olivine type lithium manganese phosphate (LiMnPO 4 ). Examples thereof include lithium acid compounds. Here, Md represents one or more kinds of transition metals having an average oxidation state of 3+, and examples thereof include Mn, Fe, and Co. In addition, y represents a number satisfying 0 ≦ y ≦ 2. Furthermore, in the olivine type lithium phosphate compound represented by Li y MdPO 4 , Md may be partially substituted with another metal. Examples of the replaceable metal include Cu, Mg, Zn, V, Ca, Sr, Ba, Ti, Al, Si, B and Mo.
［負極活物質］
　また、負極活物質としては、例えば、炭素系負極活物質、金属系負極活物質、およびこれらを組み合わせた負極活物質などが挙げられる。 [Negative electrode active material]
Further, examples of the negative electrode active material include a carbon-based negative electrode active material, a metal-based negative electrode active material, and a negative electrode active material combining these.
　ここで、炭素系負極活物質とは、リチウムを挿入（「ドープ」ともいう。）可能な、炭素を主骨格とする活物質をいい、炭素系負極活物質としては、例えば炭素質材料と黒鉛質材料とが挙げられる。 Here, the carbon-based negative electrode active material refers to an active material having lithium as a main skeleton, into which lithium can be inserted (also referred to as “dope”). Examples of the carbon-based negative electrode active material include a carbonaceous material and graphite. Quality materials.
　炭素質材料は、炭素前駆体を２０００℃以下で熱処理して炭素化させることによって得られる、黒鉛化度の低い（即ち、結晶性の低い）材料である。なお、炭素化させる際の熱処理温度の下限は特に限定されないが、例えば５００℃以上とすることができる。
　そして、炭素質材料としては、例えば、熱処理温度によって炭素の構造を容易に変える易黒鉛性炭素や、ガラス状炭素に代表される非晶質構造に近い構造を持つ難黒鉛性炭素などが挙げられる。
　ここで、易黒鉛性炭素としては、例えば、石油または石炭から得られるタールピッチを原料とした炭素材料が挙げられる。具体例を挙げると、コークス、メソカーボンマイクロビーズ（ＭＣＭＢ）、メソフェーズピッチ系炭素繊維、熱分解気相成長炭素繊維などが挙げられる。
　また、難黒鉛性炭素としては、例えば、フェノール樹脂焼成体、ポリアクリロニトリル系炭素繊維、擬等方性炭素、フルフリルアルコール樹脂焼成体（ＰＦＡ）、ハードカーボンなどが挙げられる。 The carbonaceous material is a material having a low degree of graphitization (that is, low crystallinity) obtained by heat-treating a carbon precursor at 2000 ° C. or lower to carbonize it. The lower limit of the heat treatment temperature for carbonization is not particularly limited, but may be 500 ° C. or higher, for example.
Examples of the carbonaceous material include graphitizable carbon that easily changes the carbon structure depending on the heat treatment temperature and non-graphitizable carbon having a structure close to an amorphous structure represented by glassy carbon. .
Here, examples of the graphitizable carbon include a carbon material obtained from tar pitch obtained from petroleum or coal as a raw material. Specific examples thereof include coke, mesocarbon microbeads (MCMB), mesophase pitch carbon fibers, and pyrolytic vapor growth carbon fibers.
Examples of the non-graphitizable carbon include a fired phenol resin, a polyacrylonitrile-based carbon fiber, pseudo isotropic carbon, a furfuryl alcohol resin fired body (PFA), and hard carbon.
　黒鉛質材料は、易黒鉛性炭素を２０００℃以上で熱処理することによって得られる、黒鉛に近い高い結晶性を有する材料である。なお、熱処理温度の上限は、特に限定されないが、例えば５０００℃以下とすることができる。
　そして、黒鉛質材料としては、例えば、天然黒鉛、人造黒鉛などが挙げられる。
　ここで、人造黒鉛としては、例えば、易黒鉛性炭素を含んだ炭素を主に２８００℃以上で熱処理した人造黒鉛、ＭＣＭＢを２０００℃以上で熱処理した黒鉛化ＭＣＭＢ、メソフェーズピッチ系炭素繊維を２０００℃以上で熱処理した黒鉛化メソフェーズピッチ系炭素繊維などが挙げられる。 The graphitic material is a material having high crystallinity close to that of graphite, which is obtained by heat-treating graphitizable carbon at 2000 ° C. or higher. The upper limit of the heat treatment temperature is not particularly limited, but may be 5000 ° C. or lower, for example.
Examples of the graphite material include natural graphite and artificial graphite.
Here, as the artificial graphite, for example, artificial graphite obtained by heat-treating carbon containing easily graphitizable carbon at 2800 ° C. or higher, graphitized MCMB obtained by heat-treating MCMB at 2000 ° C. or higher, and mesophase pitch-based carbon fiber at 2000 ° C. Examples include the graphitized mesophase pitch-based carbon fiber heat-treated as described above.
　また、金属系負極活物質とは、金属を含む活物質であり、通常は、リチウムの挿入が可能な元素を構造に含み、リチウムが挿入された場合の単位質量当たりの理論電気容量が５００ｍＡｈ／ｇ以上である活物質をいう。金属系活物質としては、例えば、リチウム金属、リチウム合金を形成し得る単体金属（例えば、Ａｇ、Ａｌ、Ｂａ、Ｂｉ、Ｃｕ、Ｇａ、Ｇｅ、Ｉｎ、Ｎｉ、Ｐ、Ｐｂ、Ｓｂ、Ｓｉ、Ｓｎ、Ｓｒ、Ｚｎ、Ｔｉなど）およびその合金、並びに、それらの酸化物、硫化物、窒化物、ケイ化物、炭化物、燐化物などが用いられる。これらの中でも、金属系負極活物質としては、ケイ素を含む活物質（シリコン系負極活物質）が好ましい。シリコン系負極活物質を用いることにより、リチウムイオン二次電池を高容量化することができるからである。 Further, the metal-based negative electrode active material is an active material containing a metal, and usually has a structure containing an element capable of inserting lithium, and has a theoretical electric capacity per unit mass of 500 mAh / when lithium is inserted. An active material having a weight of at least g. Examples of the metal-based active material include lithium metal and elemental metals capable of forming a lithium alloy (for example, Ag, Al, Ba, Bi, Cu, Ga, Ge, In, Ni, P, Pb, Sb, Si, Sn). , Sr, Zn, Ti, etc.) and alloys thereof, and their oxides, sulfides, nitrides, silicides, carbides, phosphides and the like. Among these, as the metal-based negative electrode active material, an active material containing silicon (silicon-based negative electrode active material) is preferable. This is because the lithium-ion secondary battery can have a high capacity by using the silicon-based negative electrode active material.
　シリコン系負極活物質としては、例えば、ケイ素（Ｓｉ）、ケイ素を含む合金、ＳｉＯ、ＳｉＯx、Ｓｉ含有材料を導電性カーボンで被覆または複合化してなるＳｉ含有材料と導電性カーボンとの複合化物などが挙げられる。なお、これらのシリコン系負極活物質は、１種類を単独で用いてもよいし、２種類上を組み合わせて用いてもよい。 As the silicon-based negative electrode active material, for example, silicon (Si), an alloy containing silicon, SiO, SiO x , a compound of Si-containing material and conductive carbon obtained by coating or compounding Si-containing material with conductive carbon. And so on. Note that these silicon-based negative electrode active materials may be used alone or in combination of two or more.
　ケイ素を含む合金としては、例えば、ケイ素と、アルミニウムと、鉄などの遷移金属とを含み、さらにスズおよびイットリウム等の希土類元素を含む合金組成物が挙げられる。 Examples of the alloy containing silicon include an alloy composition containing silicon, aluminum, a transition metal such as iron, and a rare earth element such as tin and yttrium.
　ＳｉＯxは、ＳｉＯおよびＳｉＯ2の少なくとも一方と、Ｓｉとを含有する化合物であり、ｘは、通常、０．０１以上２未満である。そして、ＳｉＯxは、例えば、一酸化ケイ素（ＳｉＯ）の不均化反応を利用して形成することができる。具体的には、ＳｉＯxは、ＳｉＯを、任意にポリビニルアルコールなどのポリマーの存在下で熱処理し、ケイ素と二酸化ケイ素とを生成させることにより、調製することができる。なお、熱処理は、ＳｉＯと、任意にポリマーとを粉砕混合した後、有機物ガス及び／又は蒸気を含む雰囲気下、９００℃以上、好ましくは１０００℃以上の温度で行うことができる。 SiO x is a compound containing at least one of SiO and SiO 2 and Si, and x is usually 0.01 or more and less than 2. Then, SiO x can be formed by utilizing, for example, a disproportionation reaction of silicon monoxide (SiO). Specifically, SiO x can be prepared by heat treating SiO, optionally in the presence of a polymer such as polyvinyl alcohol, to produce silicon and silicon dioxide. The heat treatment can be carried out at a temperature of 900 ° C. or higher, preferably 1000 ° C. or higher in an atmosphere containing organic gas and / or vapor after pulverizing and mixing SiO and optionally a polymer.
　Ｓｉ含有材料と導電性カーボンとの複合化物としては、例えば、ＳｉＯと、ポリビニルアルコールなどのポリマーと、任意に炭素材料との粉砕混合物を、例えば有機物ガスおよび／または蒸気を含む雰囲気下で熱処理してなる化合物を挙げることができる。また、複合化物は、ＳｉＯの粒子に対して、有機物ガスなどを用いた化学的蒸着法によって表面をコーティングする方法、ＳｉＯの粒子と黒鉛または人造黒鉛をメカノケミカル法によって複合粒子化（造粒化）する方法などの公知の方法でも得ることができる。 As the composite of the Si-containing material and conductive carbon, for example, a pulverized mixture of SiO, a polymer such as polyvinyl alcohol, and optionally a carbon material is heat-treated under an atmosphere containing, for example, an organic gas and / or steam. The compound can be mentioned. In addition, the composite compound is a method of coating the surface of SiO particles by a chemical vapor deposition method using an organic gas, a composite particle of SiO particles and graphite or artificial graphite by a mechanochemical method (granulation). It can also be obtained by a known method such as
＜スラリー組成物の全固形分質量に対する炭素系負極活物質の質量の割合（炭素系負極活物質の質量／スラリー組成物の全固形分質量）＞
　スラリー組成物の全固形分質量に対する炭素系負極活物質の質量の割合（炭素系負極活物質の質量／スラリー組成物の全固形分質量）としては、５０質量％以上であることが好ましく、６０質量％以上であることがより好ましく、また、９０質量％以下であることが好ましく、８５質量％以下であることがより好ましい。前記割合を上記下限値以上とすることで、炭素系負極活物質（黒鉛）の金属系負極活物質（シリコン系活物質）の緩衝作用が低減するのを抑制して、セル容量の低下を抑制することができる。一方、前記割合を上記上限値以下とすることで、得られる二次電池のサイクル特性を向上させることができる。 <Ratio of the mass of the carbon-based negative electrode active material to the mass of the total solid content of the slurry composition (mass of the carbon-based negative electrode active material / mass of the total solid content of the slurry composition)>
The ratio of the mass of the carbon-based negative electrode active material to the mass of the total solid content of the slurry composition (mass of the carbon-based negative electrode active material / mass of the total solid content of the slurry composition) is preferably 50 mass% or more, 60 It is more preferably at least mass%, preferably at most 90 mass%, more preferably at most 85 mass%. By setting the above ratio to the above lower limit or more, it is possible to suppress a decrease in the buffering effect of the metal-based negative electrode active material (silicon-based active material) of the carbon-based negative electrode active material (graphite), and to suppress a decrease in cell capacity. can do. On the other hand, by setting the above ratio to the above upper limit value or less, the cycle characteristics of the obtained secondary battery can be improved.
＜スラリー組成物の全固形分質量に対する金属系負極活物質の質量の割合（金属系負極活物質の質量／スラリー組成物の全固形分質量）＞
　スラリー組成物の全固形分質量に対する金属系負極活物質の質量の割合（金属系負極活物質の質量／スラリー組成物の全固形分質量）としては、５質量％以上であることが好ましく、１０質量％以上であることがより好ましく、また、４０質量％以下であることが好ましく、３０質量％以下であることがより好ましい。前記割合を上記下限値以上とすることで、セル容量の低下を抑制することができる。一方、前記割合を上記上限値以下とすることで、得られる二次電池のサイクル特性を向上させることができる。 <Ratio of the mass of the metal-based negative electrode active material to the mass of the total solid content of the slurry composition (mass of the metal-based negative electrode active material / mass of the total solid content of the slurry composition)>
The ratio of the mass of the metal-based negative electrode active material to the mass of the total solid content of the slurry composition (mass of the metal-based negative electrode active material / mass of the total solid content of the slurry composition) is preferably 5 mass% or more. It is more preferably at least mass%, preferably at most 40 mass%, more preferably at most 30 mass%. By setting the above ratio to the above lower limit or more, it is possible to suppress the decrease in cell capacity. On the other hand, by setting the above ratio to the above upper limit value or less, the cycle characteristics of the obtained secondary battery can be improved.
＜その他の成分＞
　二次電池用スラリー組成物は、上述した成分以外にも、その他の任意の成分を含んでいてもよい。前記任意の成分は、機能層（多孔膜層、接着層、または電極層）を用いた二次電池における電池反応に過度に好ましくない影響を及ぼさないものであれば、特に制限は無い。また、前記任意の成分の種類は、１種類でもよく、２種類以上でもよい。
　前記任意の成分としては、例えば、粒子状結着材（重合体Ｂに該当するものを除く）、濡れ剤、レベリング剤、電解液分解抑制剤、などが挙げられる。 <Other ingredients>
The slurry composition for a secondary battery may contain any other component in addition to the components described above. The optional component is not particularly limited as long as it does not unduly affect the battery reaction in the secondary battery using the functional layer (porous film layer, adhesive layer, or electrode layer). Further, the type of the arbitrary component may be one type or two or more types.
Examples of the optional component include a particulate binder (excluding those corresponding to the polymer B), a wetting agent, a leveling agent, an electrolytic solution decomposition inhibitor, and the like.
＜二次電池用スラリー組成物の調製＞
　上述した二次電池用スラリー組成物は、例えば、上記各成分を分散媒としての水系媒体中に分散させることにより調製することができる。具体的には、ボールミル、サンドミル、ビーズミル、顔料分散機、らい潰機、超音波分散機、ホモジナイザー、プラネタリーミキサー、フィルミックスなどの混合機を用いて上記各成分と水系媒体とを混合することにより、二次電池用スラリー組成物を調製することができる。ここで、また、高い分散シェアを加えることができる観点から、ビーズミル、ロールミル、フィルミックス等の高分散装置を用いてもよい。なお、上記各成分と水系媒体との混合は、通常、室温～８０℃の範囲で、１０分～数時間行うことができる。
　ここで、水系媒体としては、通常は水を用いるが、任意の化合物の水溶液や、少量の有
機媒体と水との混合溶液などを用いてもよい。なお、水系媒体として使用される水には、
バインダー組成物が含有していた水も含まれ得る。 <Preparation of slurry composition for secondary battery>
The above-described secondary battery slurry composition can be prepared, for example, by dispersing the above components in an aqueous medium as a dispersion medium. Specifically, a ball mill, a sand mill, a bead mill, a pigment disperser, a crusher, an ultrasonic disperser, a homogenizer, a planetary mixer, and a mix of the above-mentioned components and an aqueous medium using a mixer such as fill mix. Thus, the slurry composition for a secondary battery can be prepared. Here, from the viewpoint that a high dispersion share can be added, a high dispersion device such as a bead mill, a roll mill or a fill mix may be used. The above components and the aqueous medium can be mixed generally at room temperature to 80 ° C. for 10 minutes to several hours.
Here, water is usually used as the aqueous medium, but an aqueous solution of an arbitrary compound, a mixed solution of a small amount of an organic medium and water, or the like may be used. In addition, the water used as an aqueous medium,
The water that the binder composition contained may also be included.
（二次電池用機能層）
　本発明の二次電池用機能層は、好ましくは上述した非導電性微粒子または上述した電極活物質を含む二次電池用スラリー組成物から形成されたものであり、例えば、上述した二次電池用スラリー組成物を適切な基材の表面に塗布して塗膜を形成した後、形成した塗膜を乾燥することにより、形成することができる。即ち、本発明の二次電池用機能層は、上述した二次電池用スラリー組成物の乾燥物よりなり、通常、上記重合体Ａと、上記非導電性微粒子または上記電極活物質と、任意に上記重合体Ｂ、上記化合物Ｘ、および／または上記その他の成分とを含有する。
　なお、本発明の二次電池用機能層に含まれる各成分（水などの分散媒を除く）の存在比は、通常、上述した二次電池用スラリー組成物中に含まれる各成分の存在比と同様となり、二次電池用機能層中の各成分の好適な存在比も、上述した二次電池用スラリー組成物中の各成分の好適な存在比と同様である。
　そして、本発明の二次電池用機能層は、本発明の二次電池用スラリー組成物から形成されているため、また耐熱性や強度に優れる多孔膜層または電極層として良好に機能する。加えて、本発明の二次電池用機能層は、二次電池のサイクル特性などの電池特性を高めることができる。 (Functional layer for secondary battery)
The functional layer for a secondary battery of the present invention is preferably formed from a slurry composition for a secondary battery containing the non-conductive fine particles described above or the electrode active material described above, and for example, for the secondary battery described above. It can be formed by applying the slurry composition to the surface of a suitable substrate to form a coating film, and then drying the formed coating film. That is, the functional layer for a secondary battery of the present invention is composed of a dried product of the above-described slurry composition for a secondary battery, and is usually the polymer A, the non-conductive fine particles or the electrode active material, and optionally It contains the polymer B, the compound X, and / or the other components.
The abundance ratio of each component (excluding a dispersion medium such as water) contained in the secondary battery functional layer of the present invention is usually the abundance ratio of each component contained in the above-described secondary battery slurry composition. Similarly, the preferable abundance ratio of each component in the secondary battery functional layer is the same as the preferable abundance ratio of each component in the above-described secondary battery slurry composition.
Since the functional layer for a secondary battery of the present invention is formed from the slurry composition for a secondary battery of the present invention, it also functions well as a porous membrane layer or an electrode layer having excellent heat resistance and strength. In addition, the functional layer for secondary batteries of the present invention can improve battery characteristics such as cycle characteristics of the secondary battery.
＜基材＞
　二次電池用機能層を形成する基材としては、特に限定されず、例えばセパレータの一部を構成する部材として二次電池用機能層を使用する場合には、基材としてはセパレータ基材を用いることができ、また、電極の一部を構成する部材として機能層を使用する場合には、基材として、集電体を用いてもよく、集電体上に電極層を形成してなる電極基材を用いてもよい。また、基材上に形成した機能層の用法に特に制限は無く、例えばセパレータ基材等の上に機能層（多孔膜層）を形成してそのままセパレータ等の電池部材として使用してもよいし、集電体上に機能層（電極層）を形成して電極として使用してもよいし、電極基材上に機能層（多孔膜層）を形成して電極として使用してもよいし、離型基材上に形成した機能層を基材から一度剥離し、他の基材に貼り付けて電池部材として使用してもよい。
　しかし、機能層から離型基材を剥がす工程を省略して電池部材の製造効率を高める観点からは、基材としてセパレータ基材、集電体、又は電極基材を用いることが好ましい。 <Substrate>
The base material forming the secondary battery functional layer is not particularly limited, and for example, when the secondary battery functional layer is used as a member forming a part of the separator, the base material is a separator base material. In addition, when a functional layer is used as a member forming a part of an electrode, a current collector may be used as a base material, and an electrode layer is formed on the current collector. You may use an electrode base material. The usage of the functional layer formed on the base material is not particularly limited, and for example, the functional layer (porous membrane layer) may be formed on the separator base material or the like and used as it is as a battery member such as a separator. The functional layer (electrode layer) may be formed on the current collector and used as the electrode, or the functional layer (porous membrane layer) may be formed on the electrode base material and used as the electrode. The functional layer formed on the release base material may be once peeled from the base material and attached to another base material to be used as a battery member.
However, from the viewpoint of omitting the step of peeling the release base material from the functional layer and increasing the production efficiency of the battery member, it is preferable to use a separator base material, a current collector, or an electrode base material as the base material.
［セパレータ基材］
　セパレータ基材としては、特に限定されないが、有機セパレータ基材などの既知のセパレータ基材が挙げられる。有機セパレータ基材は、有機材料からなる多孔性部材であり、有機セパレータ基材の例を挙げると、ポリエチレン、ポリプロピレン等のポリオレフィン樹脂、芳香族ポリアミド樹脂などを含む微多孔膜などが挙げられ、強度に優れることからポリエチレン製の微多孔膜が好ましい。なお、有機セパレータ基材の厚さは、任意の厚さとすることができ、通常０．５μｍ以上、好ましくは５μｍ以上であり、通常４０μｍ以下、好ましくは３０μｍ以下、より好ましくは２０μｍ以下である。 [Separator base material]
The separator substrate is not particularly limited, and examples thereof include known separator substrates such as organic separator substrates. The organic separator base material is a porous member made of an organic material, and examples of the organic separator base material include polyethylene, polyolefin resins such as polypropylene, and microporous membranes containing an aromatic polyamide resin, and the like. A microporous membrane made of polyethylene is preferable because it is excellent. The thickness of the organic separator substrate can be any thickness, and is usually 0.5 μm or more, preferably 5 μm or more, and is usually 40 μm or less, preferably 30 μm or less, more preferably 20 μm or less.
［集電体］
　集電体としては、特に限定されず、既知の集電体を用いることができる。このような既知の集電体としては、例えば「二次電池用電極層」の項で後述するものが挙げられる。 [Current collector]
The current collector is not particularly limited, and a known current collector can be used. Examples of such a known current collector include those described later in the section of "electrode layer for secondary battery".
［電極基材］
　電極基材（正極基材および負極基材）としては、特に限定されないが、集電体上に電極層が形成された電極基材が挙げられる。
　ここで、集電体、電極層中の電極活物質（正極活物質、負極活物質）および電極層用結着材（正極合材層用結着材、負極合材層用結着材）、並びに、集電体上への電極層の形成方法は、既知のものを用いることができ、例えば特開２０１３－１４５７６３号公報に記載のものが挙げられる。また電極層用結着材として、本発明の二次電池用バインダー組成物に含まれる重合体Ａを使用してもよい。 [Electrode substrate]
The electrode base material (positive electrode base material and negative electrode base material) is not particularly limited, and examples thereof include an electrode base material having an electrode layer formed on a current collector.
Here, a current collector, an electrode active material in the electrode layer (positive electrode active material, negative electrode active material) and an electrode layer binder (positive electrode composite material layer binder, negative electrode composite material layer binder), In addition, a known method can be used for forming the electrode layer on the current collector, and examples thereof include those described in JP-A-2013-145763. Further, the polymer A contained in the binder composition for a secondary battery of the present invention may be used as the binder for the electrode layer.
［離型基材］
　機能層を形成する離型基材としては、特に限定されず、既知の離型基材を用いることができる。 [Release substrate]
The release base material for forming the functional layer is not particularly limited, and a known release base material can be used.
＜二次電池用機能層の形成方法＞
　上述したセパレータ基材、集電体、電極基材などの基材上に機能層を形成する方法としては、以下の方法が挙げられる。
１）二次電池用スラリー組成物をセパレータ基材、集電体又は電極基材の表面に塗布し、次いで乾燥する方法；
２）二次電池用スラリー組成物にセパレータ基材、集電体又は電極基材を浸漬後、これを乾燥する方法；
３）二次電池用スラリー組成物を、離型基材上に塗布、乾燥して機能層を製造し、得られた二次電池用機能層をセパレータ基材、集電体又は電極基材の表面に転写する方法；
　これらの中でも、前記１）の方法が、二次電池用機能層の膜厚制御をしやすいことから特に好ましい。該１）の方法は、詳細には、二次電池用スラリー組成物を基材（セパレータ基材、集電体又は電極基材）上に塗布する工程（塗布工程）、基材（セパレータ基材、集電体又は電極基材）上に塗布された二次電池用スラリー組成物を乾燥させて機能層を形成する工程（機能層形成工程）を含む。 <Method for forming functional layer for secondary battery>
Examples of the method for forming a functional layer on a substrate such as the separator substrate, the current collector, and the electrode substrate described above include the following methods.
1) A method of applying the slurry composition for a secondary battery to the surface of a separator substrate, a current collector or an electrode substrate, and then drying.
2) A method of immersing the separator base material, the current collector or the electrode base material in the slurry composition for a secondary battery, and then drying it.
3) The functional composition for secondary batteries is manufactured by applying the slurry composition for secondary batteries on a release base material and drying it, and using the obtained functional layer for secondary batteries as a separator base material, a collector or an electrode base material. Method of transferring to the surface;
Among these, the method 1) is particularly preferable because it is easy to control the film thickness of the secondary battery functional layer. The method 1) is specifically a step (application step) of applying the slurry composition for a secondary battery onto a base material (separator base material, current collector or electrode base material), base material (separator base material). , A current collector or an electrode base material) is dried to form a functional layer (functional layer forming step).
［塗布工程］
　塗布工程において、二次電池用スラリー組成物を基材上に塗布する方法は、特に制限は無く、例えば、ドクターブレード法、リバースロール法、ダイレクトロール法、グラビア法、エクストルージョン法、ハケ塗り法などの方法が挙げられる。 [Coating process]
In the coating step, the method of coating the secondary battery slurry composition on the substrate is not particularly limited, for example, doctor blade method, reverse roll method, direct roll method, gravure method, extrusion method, brush coating method. And the like.
［機能層形成工程］
　また、機能層形成工程において、基材上の二次電池用スラリー組成物を乾燥する方法としては、特に限定されず公知の方法を用いることができ、例えば温風、熱風、低湿風による乾燥、真空乾燥、赤外線や電子線などの照射による乾燥法が挙げられる。乾燥条件は特に限定されないが、乾燥温度は好ましくは５０～１００℃で、乾燥時間は好ましくは５～３０分である。
　なお、基材上に形成された二次電池用機能層の厚さは、適宜調整することができる。 [Functional layer forming process]
Further, in the functional layer forming step, as a method of drying the secondary battery slurry composition on the substrate, a known method can be used without particular limitation, for example, hot air, hot air, drying with low humidity air, Examples thereof include vacuum drying and a drying method by irradiation with infrared rays or electron beams. The drying conditions are not particularly limited, but the drying temperature is preferably 50 to 100 ° C., and the drying time is preferably 5 to 30 minutes.
The thickness of the secondary battery functional layer formed on the base material can be appropriately adjusted.
（二次電池用機能層の製造方法）
　そして、本発明の二次電池用機能層の製造方法は、本発明の二次電池用機能層を製造する方法であって、塗布工程と、真空乾燥工程と、を含む。 (Method for manufacturing functional layer for secondary battery)
And the manufacturing method of the functional layer for secondary batteries of this invention is a method of manufacturing the functional layer for secondary batteries of this invention, Comprising: A coating process and a vacuum drying process are included.
＜塗布工程＞
　塗布工程は、基材上に、上述した本発明の二次電池用スラリー組成物を塗布する工程である。
　塗布工程において、二次電池用スラリー組成物を基材上に塗布する方法は、特に制限は無く、例えば、ドクターブレード法、リバースロール法、ダイレクトロール法、グラビア法、エクストルージョン法、ハケ塗り法などの方法が挙げられる。 <Coating process>
The coating step is a step of coating the above-described secondary battery slurry composition of the present invention on a substrate.
In the coating step, the method of coating the secondary battery slurry composition on the substrate is not particularly limited, for example, doctor blade method, reverse roll method, direct roll method, gravure method, extrusion method, brush coating method. And the like.
＜真空乾燥工程＞
　真空乾燥工程は、塗布工程において塗布された二次電池用スラリー組成物を真空乾燥する工程である。
　なお、本発明において、「二次電池用スラリー組成物を真空乾燥する」とは、液状の二次電池用スラリー組成物から分散媒（溶媒）を除去して機能層を作製する一連の過程において真空乾燥を施すことを意味し、スラリー組成物の溶媒の大部分が除去されて乾燥物となり、実質的に機能層が形成された状態での真空乾燥も含まれる。そして、当該真空乾燥は、スラリー組成物の乾燥物を備える電池部材を二次電池に組み込んだ後で行ってもよい。
　真空乾燥の条件としては、例えば、乾燥温度が５０℃以上２００℃以下であり、乾燥時間が３６０分間以上１２００分間以下である。
　なお、真空乾燥により、上述したけん化された共重合体における水酸基同士の脱水縮合を行うことができる。 <Vacuum drying process>
The vacuum drying step is a step of vacuum-drying the secondary battery slurry composition applied in the applying step.
In the present invention, "vacuum-drying a secondary battery slurry composition" refers to a series of processes for producing a functional layer by removing a dispersion medium (solvent) from a liquid secondary battery slurry composition. This means performing vacuum drying, and most of the solvent of the slurry composition is removed to obtain a dried product, and vacuum drying in a state where a functional layer is substantially formed is also included. And the said vacuum drying may be performed after incorporating the battery member provided with the dried material of the slurry composition into the secondary battery.
The conditions for vacuum drying are, for example, a drying temperature of 50 ° C. or higher and 200 ° C. or lower, and a drying time of 360 minutes or longer and 1200 minutes or shorter.
By vacuum drying, dehydration condensation of the hydroxyl groups in the saponified copolymer described above can be performed.
（二次電池用電極層）
　本発明の二次電池用電極層は、上述した電極活物質を含む二次電池用スラリー組成物から形成されたものであり、例えば、上述した二次電池用スラリー組成物を適切な集電体の表面に塗布して塗膜を形成した後、形成した塗膜を乾燥することにより、形成することができる。即ち、本発明の二次電池用電極層は、上述した二次電池用スラリー組成物の乾燥物よりなり、通常、上記重合体Ａと、上記電極活物質と、上記任意の重合体Ｂと、上記任意の化合物Ｘと、任意に上記その他の成分とを含有する。
　なお、二次電池用電極層は、二次電池用機能層に含まれる（換言すると、二次電池用電極層は、二次電池用機能層の一例である）。
　なお、本発明の二次電池用電極層に含まれる各成分（水などの分散媒を除く）の存在比は、通常、上述した二次電池用スラリー組成物中に含まれる各成分の存在比と同様となり、二次電池用電極層中の各成分の好適な存在比も、上述した二次電池用スラリー組成物中の各成分の好適な存在比と同様である。
　そして、本発明の二次電池用電極層は、本発明の二次電池用スラリー組成物から形成されているため、高いピール強度を有し、且つ、二次電池に優れたサイクル特性を発揮させることができる。 (Secondary battery electrode layer)
The electrode layer for a secondary battery of the present invention is formed from a slurry composition for a secondary battery containing the above-mentioned electrode active material, and for example, a suitable current collector for the slurry composition for a secondary battery described above. It can be formed by applying the coating to the surface of to form a coating film and then drying the formed coating film. That is, the electrode layer for a secondary battery of the present invention is a dried product of the slurry composition for a secondary battery described above, and is usually the polymer A, the electrode active material, and the optional polymer B, It contains the above-mentioned optional compound X and optionally the above-mentioned other components.
The secondary battery electrode layer is included in the secondary battery functional layer (in other words, the secondary battery electrode layer is an example of the secondary battery functional layer).
The abundance ratio of each component (excluding a dispersion medium such as water) contained in the secondary battery electrode layer of the present invention is usually the abundance ratio of each component contained in the above-described secondary battery slurry composition. Similarly, the preferable abundance ratio of each component in the secondary battery electrode layer is the same as the preferable abundance ratio of each component in the above-described secondary battery slurry composition.
Since the secondary battery electrode layer of the present invention is formed from the secondary battery slurry composition of the present invention, it has high peel strength, and makes the secondary battery exhibit excellent cycle characteristics. be able to.
＜二次電池用電極層の形成方法＞
　なお、本発明の二次電池用電極層は、例えば、上述した二次電池用スラリー組成物を集電体上に塗布する工程（塗布工程）と、集電体上に塗布された二次電池用スラリー組成物を乾燥して集電体上に電極層を形成する工程（乾燥工程）とを経て形成される。 <Method for forming electrode layer for secondary battery>
The secondary battery electrode layer of the present invention includes, for example, a step of applying the above-described secondary battery slurry composition on a current collector (application step) and a secondary battery applied on the current collector. The slurry composition is dried to form an electrode layer on the current collector (drying step).
［塗布工程］
　上記二次電池用スラリー組成物を集電体上に塗布する方法としては、特に限定されず公知の方法を用いることができる。具体的には、塗布方法としては、ドクターブレード法、ディップ法、リバースロール法、ダイレクトロール法、グラビア法、エクストルージョン法、ハケ塗り法などを用いることができる。この際、スラリー組成物を集電体の片面だけに塗布してもよいし、両面に塗布してもよい。塗布後乾燥前の集電体上のスラリー膜の厚みは、乾燥して得られる電極層の厚みに応じて適宜に設定しうる。 [Coating process]
The method for applying the slurry composition for a secondary battery on the current collector is not particularly limited, and a known method can be used. Specifically, as a coating method, a doctor blade method, a dipping method, a reverse roll method, a direct roll method, a gravure method, an extrusion method, a brush coating method or the like can be used. At this time, the slurry composition may be applied to only one surface of the current collector or both surfaces thereof. The thickness of the slurry film on the current collector after coating and before drying can be appropriately set according to the thickness of the electrode layer obtained by drying.
　ここで、二次電池用スラリー組成物を塗布する集電体としては、電気導電性を有し、かつ、電気化学的に耐久性のある材料が用いられる。具体的には、集電体としては、例えば、鉄、銅、アルミニウム、ニッケル、ステンレス鋼、チタン、タンタル、金、白金などからなる集電体を用い得る。中でも、負極に用いる集電体としては、銅箔が特に好ましい。また、正極に用いる集電体としては、アルミニウム箔が特に好ましい。なお、前記の材料は、１種類を単独で用いてもよく、２種類以上を任意の比率で組み合わせて用いてもよい。 Here, as a current collector for applying the secondary battery slurry composition, a material having electrical conductivity and electrochemical durability is used. Specifically, as the current collector, for example, a current collector made of iron, copper, aluminum, nickel, stainless steel, titanium, tantalum, gold, platinum, or the like can be used. Among them, copper foil is particularly preferable as the current collector used for the negative electrode. An aluminum foil is particularly preferable as the current collector used for the positive electrode. In addition, the said material may be used individually by 1 type and may be used in combination of 2 or more types by arbitrary ratios.
［乾燥工程］
　集電体上の二次電池用スラリー組成物を乾燥する方法としては、特に限定されず公知の方法を用いることができ、例えば温風、熱風、低湿風による乾燥、真空乾燥、赤外線や電子線などの照射による乾燥法が挙げられる。このように集電体上の二次電池用スラリー組成物を乾燥することで、集電体上に電極層を形成し、集電体と電極層とを備える二次電池用電極を得ることができる。 [Drying process]
The method for drying the secondary battery slurry composition on the current collector is not particularly limited and known methods can be used, for example, hot air, hot air, low-humid air drying, vacuum drying, infrared rays or electron beams. And a drying method by irradiation. By thus drying the secondary battery slurry composition on the current collector, an electrode layer is formed on the current collector, and a secondary battery electrode including the current collector and the electrode layer can be obtained. it can.
　なお、乾燥工程の後、金型プレスまたはロールプレスなどを用い、電極層に加圧処理（プレス加工）を施してもよい。プレス加工により、電極層と集電体との密着性を向上させることができる。また、電極層を高密度化し、二次電池を小型化することができる。 After the drying step, the electrode layer may be subjected to pressure treatment (pressing) using a die press or roll press. By press working, the adhesion between the electrode layer and the current collector can be improved. In addition, the density of the electrode layer can be increased and the secondary battery can be downsized.
（二次電池）
　本発明の二次電池は、上述した本発明の二次電池用機能層を備えるものである。より具体的には、本発明の二次電池は、正極、負極、セパレータ、および電解液を備え、上述した二次電池用機能層が、電池部材である正極、負極およびセパレータの少なくとも１つに含まれる。
　本発明の二次電池は、本発明の二次電池用機能層を備えているので、安全性に優れた二次電池用機能層を有し、サイクル特性に優れる。 (Secondary battery)
The secondary battery of the present invention comprises the above-mentioned functional layer for a secondary battery of the present invention. More specifically, the secondary battery of the present invention includes a positive electrode, a negative electrode, a separator, and an electrolytic solution, and the above-mentioned secondary battery functional layer is provided in at least one of the positive electrode, the negative electrode, and the separator that are battery members. included.
Since the secondary battery of the present invention includes the functional layer for a secondary battery of the present invention, it has a functional layer for a secondary battery having excellent safety and excellent cycle characteristics.
＜正極、負極およびセパレータ＞
　本発明の二次電池に用いる正極、負極およびセパレータは、少なくとも一つが本発明の二次電池用機能層を有している。具体的には、二次電池用機能層を有する正極および負極としては、集電体上に二次電池用電極層としての電極層を形成してなる電極や、集電体上に二次電池用電極層としての電極層を形成してなる電極基材の上に機能層（多孔膜層）を設けてなる電極を用いることができる。また、二次電池用機能層を有するセパレータとしては、セパレータ基材の上に二次電池用機能層（多孔膜層）を設けてなるセパレータを用いることができる。なお、電極基材およびセパレータ基材としては、「基材」の項で挙げたものと同様のものを用いることができる。 <Positive electrode, negative electrode and separator>
At least one of the positive electrode, the negative electrode, and the separator used in the secondary battery of the present invention has the functional layer for secondary battery of the present invention. Specifically, as the positive electrode and the negative electrode having the functional layer for a secondary battery, an electrode formed by forming an electrode layer as a secondary battery electrode layer on a current collector, or a secondary battery on the current collector An electrode can be used in which a functional layer (porous membrane layer) is provided on an electrode base material formed by forming an electrode layer as a working electrode layer. Further, as the separator having the secondary battery functional layer, a separator obtained by providing a secondary battery functional layer (porous membrane layer) on a separator substrate can be used. As the electrode base material and the separator base material, the same materials as those mentioned in the section of "base material" can be used.
＜正極、負極＞
　上述のように、二次電池に用いる正極、負極およびセパレータの少なくとも一つが、本発明の二次電池用機能層を有していれば、負極が既知の負極であってもよく、正極が既知の正極であってもよく、そして、二次電池の正極および負極が、それぞれ既知の電極であってもよい。 <Positive electrode, negative electrode>
As described above, the negative electrode may be a known negative electrode as long as at least one of the positive electrode used for the secondary battery, the negative electrode and the separator has the functional layer for a secondary battery of the present invention, and the known positive electrode is known. The positive electrode and the negative electrode of the secondary battery may be known electrodes.
［セパレータ］
　セパレータとしては、二次電池に用いる正極および負極の少なくとも一つが、本発明の二次電池用機能層を有していれば、例えば特開２０１２－２０４３０３号公報に記載のものを用いることができる。これらの中でも、セパレータ全体の膜厚を薄くすることができ、これにより、リチウムイオン二次電池内の電極活物質の比率を高くして体積あたりの容量を高くすることができるという点より、ポリオレフィン系の樹脂（ポリエチレン、ポリプロピレン、ポリブテン、ポリ塩化ビニル）からなる微多孔膜が好ましい。 [Separator]
As the separator, for example, those described in JP 2012-204303 A can be used as long as at least one of the positive electrode and the negative electrode used in the secondary battery has the functional layer for secondary battery of the present invention. .. Among these, it is possible to reduce the thickness of the entire separator, and thereby increase the ratio of the electrode active material in the lithium-ion secondary battery to increase the capacity per volume. A microporous membrane made of a series resin (polyethylene, polypropylene, polybutene, polyvinyl chloride) is preferable.
＜電解液＞
　電解液としては、通常、有機溶媒に支持電解質を溶解した有機電解液が用いられる。支持電解質としては、例えば、リチウムイオン二次電池においてはリチウム塩が用いられる。リチウム塩としては、例えば、ＬｉＰＦ6、ＬｉＡｓＦ6、ＬｉＢＦ4、ＬｉＳｂＦ6、ＬｉＡｌＣｌ4、ＬｉＣｌＯ4、ＣＦ3ＳＯ3Ｌｉ、Ｃ4Ｆ9ＳＯ3Ｌｉ、ＣＦ3ＣＯＯＬｉ、（ＣＦ3ＣＯ）2ＮＬｉ、（ＣＦ3ＳＯ2）2ＮＬｉ、（Ｃ2Ｆ5ＳＯ2）ＮＬｉなどが挙げられる。なかでも、溶媒に溶けやすく高い解離度を示すので、ＬｉＰＦ6、ＬｉＣｌＯ4、ＣＦ3ＳＯ3Ｌｉが好ましい。なお、電解質は１種類を単独で用いてもよく、２種類以上を組み合わせて用いてもよい。通常は、解離度の高い支持電解質を用いるほどリチウムイオン伝導度が高くなる傾向があるので、支持電解質の種類によりリチウムイオン伝導度を調節することができる。 <Electrolyte>
As the electrolytic solution, an organic electrolytic solution prepared by dissolving a supporting electrolyte in an organic solvent is usually used. As the supporting electrolyte, for example, a lithium salt is used in a lithium ion secondary battery. Examples of the lithium salt include LiPF 6 , LiAsF 6 , LiBF 4 , LiSbF 6 , LiAlCl 4 , LiClO 4 , CF 3 SO 3 Li, C 4 F 9 SO 3 Li, CF 3 COOLi, (CF 3 CO) 2 NLi. , (CF 3 SO 2 ) 2 NLi, (C 2 F 5 SO 2 ) NLi, and the like. Among them, LiPF 6 , LiClO 4 , and CF 3 SO 3 Li are preferable because they are easily dissolved in a solvent and exhibit a high dissociation degree. The electrolyte may be used alone or in combination of two or more. Generally, the higher the dissociation degree of the supporting electrolyte, the higher the lithium ion conductivity tends to be, so the lithium ion conductivity can be adjusted depending on the type of the supporting electrolyte.
　電解液に使用する有機溶媒としては、支持電解質を溶解できるものであれば特に限定されないが、例えばリチウムイオン二次電池においては、ジメチルカーボネート（ＤＭＣ）、エチレンカーボネート（ＥＣ）、ジエチルカーボネート（ＤＥＣ）、プロピレンカーボネート（ＰＣ）、ブチレンカーボネート（ＢＣ）、エチルメチルカーボネート（ＥＭＣ）等のカーボネート類；γ－ブチロラクトン、ギ酸メチル等のエステル類；１，２－ジメトキシエタン、テトラヒドロフラン等のエーテル類；スルホラン、ジメチルスルホキシド等の含硫黄化合物類；などが好適に用いられる。またこれらの溶媒の混合液を用いてもよい。中でも、誘電率が高く、安定な電位領域が広いのでカーボネート類が好ましい。通常、用いる溶媒の粘度が低いほどリチウムイオン伝導度が高くなる傾向があるので、溶媒の種類によりリチウムイオン伝導度を調節することができる。
　なお、電解液中の電解質の濃度は適宜調整することができる。また、電解液には、既知の添加剤を添加してもよい。 The organic solvent used in the electrolytic solution is not particularly limited as long as it can dissolve the supporting electrolyte. For example, in a lithium ion secondary battery, dimethyl carbonate (DMC), ethylene carbonate (EC), diethyl carbonate (DEC). , Propylene carbonate (PC), butylene carbonate (BC), ethylmethyl carbonate (EMC) and other carbonates; γ-butyrolactone, methyl formate and other esters; 1,2-dimethoxyethane, tetrahydrofuran and other ethers; sulfolane, Sulfur-containing compounds such as dimethyl sulfoxide; and the like are preferably used. Moreover, you may use the mixed liquid of these solvents. Among them, carbonates are preferable because they have a high dielectric constant and a wide stable potential region. Generally, the lower the viscosity of the solvent used, the higher the lithium ion conductivity tends to be, so the lithium ion conductivity can be adjusted by the type of the solvent.
The concentration of the electrolyte in the electrolytic solution can be adjusted appropriately. Known additives may be added to the electrolytic solution.
＜二次電池の製造方法＞
　二次電池は、例えば、正極と負極とをセパレータを介して重ね合わせ、これを必要に応じて、巻く、折るなどして電池容器に入れ、電池容器に電解液を注入して封口することで製造し得る。なお、正極、負極、セパレータのうち、少なくとも一つの部材を、本発明の二次電池用機能層を有する部材とする。ここで、電池容器には、必要に応じてエキスパンドメタルや、ヒューズ、ＰＴＣ素子などの過電流防止素子、リード板などを入れ、電池内部の圧力上昇、過充放電の防止をしてもよい。電池の形状は、例えば、コイン型、ボタン型、シート型、円筒型、角形、扁平型など、何れであってもよい。 <Method of manufacturing secondary battery>
Secondary batteries, for example, by stacking a positive electrode and a negative electrode via a separator, if necessary, by winding, folding, etc. into a battery container, by pouring the electrolytic solution into the battery container and sealing it. Can be manufactured. At least one of the positive electrode, the negative electrode, and the separator is the member having the functional layer for a secondary battery of the present invention. Here, the battery container may be provided with an expanded metal, a fuse, an overcurrent preventing element such as a PTC element, a lead plate, etc., if necessary, to prevent a pressure increase in the battery and an overcharge / discharge. The shape of the battery may be, for example, a coin type, a button type, a sheet type, a cylindrical type, a prismatic type, a flat type, or the like.
　以下、本発明について実施例に基づき具体的に説明するが、本発明はこれら実施例に限定されるものではない。なお、以下の説明において、量を表す「％」および「部」は、特に断らない限り、質量基準である。
　また、複数種類の単量体を共重合して製造される重合体において、ある単量体を重合して形成される繰り返し単位（単量体単位）の前記重合体における割合は、別に断らない限り、通常は、その重合体の重合に用いる全単量体に占める当該ある単量体の比率（仕込み比）と概ね一致する。 Hereinafter, the present invention will be specifically described based on Examples, but the present invention is not limited to these Examples. In the following description, "%" and "parts" representing amounts are based on mass unless otherwise specified.
Further, in a polymer produced by copolymerizing a plurality of kinds of monomers, the proportion of the repeating unit (monomer unit) formed by polymerizing a certain monomer in the polymer is not otherwise specified. As long as it is, the ratio (feeding ratio) of a certain monomer to all the monomers used for the polymerization of the polymer is almost the same.
　実施例および比較例において、（ｉ）重合体Ａの重量平均分子量、（ｉｉ）重合体Ａの電解液膨潤度、（ｉｉｉ）重合体Ａの固形分に対する化合物Ｘの含有量、（ｉｖ）スラリー組成物の増粘、（ｖ）電極（負極合材層）のピール強度、（ｖｉ）多孔膜層（セパレータ塗工層）のピール強度、（ｖｉｉ）二次電池のサイクル特性は、下記の方法で測定および評価した。 In Examples and Comparative Examples, (i) weight average molecular weight of polymer A, (ii) electrolyte solution swelling degree of polymer A, (iii) content of compound X with respect to solid content of polymer A, (iv) slurry The thickening of the composition, (v) peel strength of the electrode (negative electrode mixture layer), (vi) peel strength of the porous membrane layer (separator coating layer), (vii) cycle characteristics of the secondary battery are as follows. Was measured and evaluated at.
＜（ｉ）重合体Ａの重量平均分子量＞
　重合体Ａの重量平均分子量を、ゲル浸透クロマトグラフィー（ＧＰＣ）により測定した。まず、溶離液約５ｍＬに、重合体Ａの固形分濃度が約０．５ｇ／Ｌとなるように加えて、室温で緩やかに溶解させた。目視で、重合体Ａの溶解を確認後、０．４５μｍフィルターにて穏やかに濾過を行い、測定用試料を調製した。そして、標準物質で検量線を作成することにより、標準物質換算値としての重量平均分子量を算出した。
　なお、測定条件は、以下のとおりである。
＜＜測定条件＞＞
　カラム：昭和電工社製、製品名Ｓｈｏｄｅｘ　ＯＨｐａｋ（ＳＢ－Ｇ，ＳＢ－８０７ＨＱ，ＳＢ－８０６ＭＨＱ）
　溶離液：０．１Ｍ　トリス緩衝液　（０．１Ｍ　塩化カリウム添加）
　流速：０．５ｍＬ／分間
　試料濃度：０．０５ｇ／Ｌ（固形分濃度）
　注入量：２００μＬ
　カラム温度：４０℃
　検出器：示差屈折率検出器ＲＩ（東ソー社製、製品名「ＲＩ－８０２０」）
　標準物質：単分散プルラン（昭和電工社製） <(I) Weight average molecular weight of polymer A>
The weight average molecular weight of the polymer A was measured by gel permeation chromatography (GPC). First, the polymer A was added to about 5 mL of the eluent so that the solid content concentration of the polymer A was about 0.5 g / L, and gently dissolved at room temperature. After visually confirming the dissolution of the polymer A, a 0.45 μm filter was gently filtered to prepare a measurement sample. Then, a weight average molecular weight as a standard substance conversion value was calculated by creating a calibration curve with the standard substance.
The measurement conditions are as follows.
<< Measurement conditions >>
Column: Showa Denko KK, product name Shodex OHpak (SB-G, SB-807HQ, SB-806MHQ)
Eluent: 0.1M Tris buffer (0.1M potassium chloride added)
Flow rate: 0.5 mL / min Sample concentration: 0.05 g / L (solid content concentration)
Injection volume: 200 μL
Column temperature: 40 ° C
Detector: differential refractive index detector RI (product name "RI-8020" manufactured by Tosoh Corporation)
Standard material: Monodisperse pullulan (Showa Denko)
＜（ｉｉ）重合体Ａの電解液膨潤度＞
　重合体Ａの電解液膨潤度を、電解液へのフィルム膨潤前後の質量変化率により測定した。
　なお、測定条件は、以下のとおりである。
＜＜測定条件＞＞
　直径４±１ｃｍのアルミ皿、またはテフロン（登録商標）皿に重合体Ａを固形分で０．５ｇとなるよう溶液で滴下し、水平台上で２５℃乾燥風を当てて２４時間乾燥させ、さらにその後、ゲージ圧－０．０８ＭＰａ以下、１００℃で５時間真空乾燥を実施した。
　電解液膨潤度測定用のフィルムとして、前記重合体Ａフィルムを露点－４０℃以下の環境下で、０．１５±０．０５ｇ分秤量し、小数点第４位まで質量を測定した。そして、フィルム０．１ｇに対して電解液１ｍｏｌ／Ｌ　ＬｉＰＦ6　ＥＣ／ＤＥＣ＝１／２（体積比　ｖｏｌ．％）（キシダ化学株式会社製　製品名：ＬＢＧ－９４９１３）を３０ｍＬ添加し、膨潤のため、６０℃７２時間窒素フロー環境下で加温した。さらに膨潤後のフィルム質量を測定した。
　電解液膨潤度（％）＝（６０℃７２時間電解液膨潤後のフィルム質量）÷（膨潤試験前のフィルム質量）×１００ <(Ii) Electrolyte Swelling Degree of Polymer A>
The electrolytic solution swelling degree of the polymer A was measured by the mass change rate before and after the film swelling in the electrolytic solution.
The measurement conditions are as follows.
<< Measurement conditions >>
Polymer A was added dropwise to an aluminum dish having a diameter of 4 ± 1 cm or a Teflon (registered trademark) dish so that the solid content was 0.5 g, and dried at 25 ° C. for 24 hours on a horizontal table by drying air. After that, vacuum drying was performed at a gauge pressure of −0.08 MPa or less at 100 ° C. for 5 hours.
As a film for measuring the degree of swelling of the electrolytic solution, the polymer A film was weighed in an amount of 0.15 ± 0.05 g in an environment having a dew point of −40 ° C. or less, and the mass was measured to the fourth decimal place. Then, 30 mL of electrolyte 1 mol / L LiPF 6 EC / DEC = 1/2 (volume ratio vol.%) (Manufactured by Kishida Chemical Co., Ltd. product name: LBG-94913) was added to 0.1 g of the film to swell. Therefore, it was heated at 60 ° C. for 72 hours in a nitrogen flow environment. Further, the mass of the film after swelling was measured.
Electrolyte swelling degree (%) = (60 ° C. 72 hours film mass after electrolyte swelling) / (film mass before swelling test) × 100
＜（ｉｉｉ）重合体Ａの固形分に対する化合物Ｘの含有量＞
　重合体Ａの固形分に対する化合物Ｘの含有量を、高速液体クロマトグラフ（ＨＰＬＣ）により測定した。
　なお、測定条件は、以下のとおりである。
＜＜測定条件＞＞
　カラム温度：４０℃
　移動相：２０ｍＭりん酸水素二カリウム水溶液／りん酸＝１０００／０．６（≒ｐＨ２．７）
　検出波長：２１０ｎｍ
　カラム：Ｓｙｎｅｒｇｉ　４μ　Ｈｙｄｒｏ－ＲＰ　８０Ａ，２５０×４．６ｍｍ（ｐｈｅｎｏｍｅｎｅｘ）（株式会社島津ジーエルシー製）
　ガードカラム：Ｓｙｎｅｒｇｉ　４μ　Ｈｙｄｒｏ－ＲＰ　８０Ａ，４×３．０ｍｍ（株式会社島津ジーエルシー製）
　流量：０．７ｍＬ／ｍｉｎ
　注入量：２０μＬ <(Iii) Content of Compound X to Solid Content of Polymer A>
The content of the compound X with respect to the solid content of the polymer A was measured by high performance liquid chromatography (HPLC).
The measurement conditions are as follows.
<< Measurement conditions >>
Column temperature: 40 ° C
Mobile phase: 20 mM dipotassium hydrogen phosphate aqueous solution / phosphoric acid = 1000 / 0.6 (≈pH 2.7)
Detection wavelength: 210nm
Column: Synergi 4μ Hydro-RP 80A, 250 × 4.6 mm (phenomenex) (manufactured by Shimadzu GLC)
Guard column: Synergi 4μ Hydro-RP 80A, 4 x 3.0 mm (manufactured by Shimadzu GC)
Flow rate: 0.7 mL / min
Injection volume: 20 μL
＜（ｉｖ）スラリー組成物の増粘＞
　調製した二次電池用スラリー組成物の粘度ηを、Ｂ型粘度計を用いて、温度２５℃、スピンドル回転速度６０ｒｐｍ、スピンドル回転時間６０秒間の条件で測定し、下記のように評価した。
　調製したスラリー組成物の、重合体Ｂ（固形分相当）１部（実施例１～１１および比較例１および２）、または、重合体Ｂ（固形分相当）３部（実施例１２）を添加する前の時点の粘度をη３とした。さらに重合体Ｂを添加し、混合した後の粘度をη４とし、それらの比率をスラリー粘度比率η５とした。
η５＝η４／η３
　スラリー粘度比率η５の値が１．０に近い程、スラリーの増粘が抑制され、スラリー組成物の調製および取り扱いが容易であることを示す。
　なお、実施例１３では、重合体Ｂを添加していないので、η３とη４とは同じ値であり、η５は１．０である。
　Ａ：スラリー粘度比率η５が１．１未満
　Ｂ：スラリー粘度比率η５が１．１以上１．２未満
　Ｃ：スラリー粘度比率η５が１．２以上１．３未満
　Ｄ：スラリー粘度比率η５が１．３以上 <(Iv) Thickening of slurry composition>
The viscosity η of the prepared secondary battery slurry composition was measured using a B-type viscometer at a temperature of 25 ° C., a spindle rotation speed of 60 rpm, and a spindle rotation time of 60 seconds, and evaluated as described below.
1 part of Polymer B (corresponding to solid content) (Examples 1 to 11 and Comparative Examples 1 and 2) or 3 parts of Polymer B (corresponding to solid content) (Example 12) of the prepared slurry composition was added. The viscosity at the point before was set as η3. Further, the viscosity after the polymer B was added and mixed was set to η4, and the ratio thereof was set to the slurry viscosity ratio η5.
η5 = η4 / η3
The closer the value of the slurry viscosity ratio η5 is to 1.0, the thicker the slurry is suppressed, and the easier the preparation and handling of the slurry composition.
In addition, since the polymer B was not added in Example 13, η3 and η4 have the same value, and η5 is 1.0.
A: Slurry viscosity ratio η5 is less than 1.1 B: Slurry viscosity ratio η5 is 1.1 or more and less than 1.2 C: Slurry viscosity ratio η5 is 1.2 or more and less than 1.3 D: Slurry viscosity ratio η5 is 1. 3 or more
＜（ｖ）電極（負極合材層）のピール強度＞
　作製した負極をそれぞれ、幅１ｃｍ×長さ１０ｃｍの矩形に切り、得られた試験片を、負極合材層面を上にして固定した。固定した試験片の負極合材層の表面にセロハンテープを貼り付けた後、試験片の一端からセロハンテープを５０ｍｍ／分の速度で１８０°方向に引き剥がしたときの応力を測定した。同様の測定を５回行い、その平均値をピール強度とし、以下の基準にて判定した。ピール強度が大きいほど、負極合材層と基材（集電体）とが良好に接着されていることを示す。
　Ａ：ピール強度が１０Ｎ／ｍ以上
　Ｂ：ピール強度が８Ｎ／ｍ以上１０Ｎ／ｍ未満
　Ｃ：ピール強度が４Ｎ／ｍ以上８Ｎ／ｍ未満
　Ｄ：ピール強度が４Ｎ／ｍ未満 <(V) Peel strength of electrode (negative electrode mixture layer)>
Each of the produced negative electrodes was cut into a rectangle having a width of 1 cm and a length of 10 cm, and the obtained test piece was fixed with the negative electrode mixture layer surface facing upward. After the cellophane tape was attached to the surface of the negative electrode mixture layer of the fixed test piece, the stress was measured when the cellophane tape was peeled off from one end of the test piece in the direction of 180 ° at a speed of 50 mm / min. The same measurement was performed 5 times, and the average value was taken as the peel strength, and judgment was made according to the following criteria. The higher the peel strength, the better the adhesion between the negative electrode mixture layer and the base material (current collector).
A: Peel strength is 10 N / m or more B: Peel strength is 8 N / m or more and less than 10 N / m C: Peel strength is 4 N / m or more and less than 8 N / m D: Peel strength is less than 4 N / m
＜（ｖｉ）多孔膜層（セパレータ塗工層）のピール強度＞
　作製した多孔膜層が塗工されたセパレータから、長さ１００ｍｍ×幅１０ｍｍの長方形の試験片を切り出した。また、予め試験台にセロハンテープを固定しておいた。このセロハンテープとしては、ＪＩＳ　Ｚ１５２２に規定されるものを用いた。
　そして、セパレータから切り出した試験片を、多孔膜層を下にしてセロハンテープに貼り付けた。その後、セパレータの一端を垂直方向に引張り速度１００ｍｍ／分で引っ張って試験片の一端からセロハンテープを剥がしたときの応力を測定した。測定を３回行い、測定した応力の平均値を求めて、これを多孔膜層のピール強度とした。そして、以下の基準で評価した。ピール強度が大きいほど、多孔膜層と基材とが良好に接着されていることを示す。
　Ａ：ピール強度が１００Ｎ／ｍ以上
　Ｂ：ピール強度が８０Ｎ／ｍ以上１００Ｎ／ｍ未満
　Ｃ：ピール強度が８０Ｎ／ｍ未満 <(Vi) Peel strength of porous membrane layer (separator coating layer)>
A rectangular test piece having a length of 100 mm and a width of 10 mm was cut out from the produced separator coated with the porous membrane layer. In addition, cellophane tape was fixed on the test table in advance. As this cellophane tape, one specified in JIS Z1522 was used.
Then, the test piece cut out from the separator was attached to the cellophane tape with the porous membrane layer facing down. Then, one end of the separator was pulled in the vertical direction at a pulling speed of 100 mm / min to measure the stress when the cellophane tape was peeled off from one end of the test piece. The measurement was performed 3 times, the average value of the measured stress was calculated | required, and this was made into the peeling strength of a porous film layer. And the following criteria evaluated. The higher the peel strength, the better the adhesion between the porous membrane layer and the substrate.
A: Peel strength is 100 N / m or more B: Peel strength is 80 N / m or more and less than 100 N / m C: Peel strength is less than 80 N / m
＜（ｖｉｉ）二次電池のサイクル特性＞
　ラミネートセル型のリチウムイオン二次電池を、電解液注液後、２５℃の環境下で、２４時間静置させた後に、０．１Ｃの定電流法により、セル電圧４．２５Ｖまで充電し、セル電圧３．０Ｖまで放電する充放電の操作を行い、初期容量Ｃ０を測定した。さらに、６０℃の環境下で、０．１Ｃの定電流法によって、セル電圧４．２５Ｖまで充電し、セル電圧３．０Ｖまで放電する充放電を繰り返し、１００サイクル後の容量Ｃ２を測定した。そして、下記式にしたがって容量維持率Ｃ３を算出した。
　Ｃ３（％）＝（Ｃ２／Ｃ０）×１００
　この値が大きいほど、サイクル特性に優れることを示す。
　Ａ：容量維持率Ｃ３が９５％以上
　Ｂ：容量維持率Ｃ３が９０％以上９５％未満
　Ｃ：容量維持率Ｃ３が８０％以上９０％未満
　Ｄ：容量維持率Ｃ３が８０％未満 <(Vii) Cycle characteristics of secondary battery>
After injecting the electrolyte solution, the laminate cell type lithium ion secondary battery was allowed to stand for 24 hours in an environment of 25 ° C. and then charged to a cell voltage of 4.25 V by a constant current method of 0.1 C, Charging / discharging operation was performed to discharge the cell voltage to 3.0 V, and the initial capacity C0 was measured. Furthermore, in an environment of 60 ° C., the cell voltage was charged to 4.25 V and discharged to a cell voltage of 3.0 V by a constant current method of 0.1 C, and charging / discharging was repeated, and the capacity C2 after 100 cycles was measured. Then, the capacity retention rate C3 was calculated according to the following formula.
C3 (%) = (C2 / C0) × 100
The larger this value is, the better the cycle characteristics are.
A: Capacity maintenance rate C3 is 95% or more B: Capacity maintenance rate C3 is 90% or more and less than 95% C: Capacity maintenance rate C3 is 80% or more and less than 90% D: Capacity maintenance rate C3 is less than 80%
（実施例１）
＜重合体Ａの調製＞
　ガラス製１Ｌフラスコに、イオン交換水７８９部を投入して、温度４０℃に加熱し、流量１００ｍＬ／分の窒素ガスでフラスコ内を置換した。次に、アミド基含有単量体としてのアクリルアミド４５部、酸官能基含有単量体としてのアクリル酸２５部、一般式（３）で表される単量体としての酢酸ビニル３０部を混合して、フラスコ内に注入した。その後、重合開始剤としての過硫酸カリウムの２．５％水溶液８．９部をシリンジでフラスコ内に添加した。過硫酸カリウムの添加から１５分後に、重合促進剤としてのテトラメチルエチレンジアミンの２．０％水溶液２２．２部をシリンジで添加し、重合反応を開始した。
　重合開始剤としての過硫酸カリウムを添加した４時間後、重合開始剤としての過硫酸カリウムの２．５％水溶液４．４部をフラスコ内に追加し、更に重合促進剤としてのテトラメチルエチレンジアミンの２．０％水溶液１１．１部を追加して、温度を６０℃まで昇温し、６０℃で維持し、重合反応を進めた。重合開始剤の追加から３時間後、フラスコを空気中に開放して重合反応を停止させ、酸官能基含有単量体および一般式（１）で表される単量体単位のモル当量分の水酸化リチウムを８％水溶液で添加し、重合生成物を温度８０℃で６時間撹拌しながら、ｐＨ７．０に調整した。その後、ｎ－ブタノールにて重合生成物を凝固させて、固形分を回収し、水溶解型の重合体Ａを得た。この重合体Ａの重量平均分子量および電解液膨潤度を測定した。また重合体Ａの固形分に対する化合物Ｘ（酢酸および酢酸塩の少なくとも何れか）の含有量を測定した。結果を何れも表１に示す。また、得られた重合体Ａについて、1Ｈ－ＮＭＲを用いて各単量体単位の含有割合を測定した。結果を表４に示す。 (Example 1)
<Preparation of Polymer A>
789 parts of ion-exchanged water was put into a glass 1 L flask, heated to a temperature of 40 ° C., and the inside of the flask was replaced with nitrogen gas having a flow rate of 100 mL / min. Next, 45 parts of acrylamide as an amide group-containing monomer, 25 parts of acrylic acid as an acid functional group-containing monomer, and 30 parts of vinyl acetate as a monomer represented by the general formula (3) are mixed. And injected into the flask. Then, 8.9 parts of a 2.5% aqueous solution of potassium persulfate as a polymerization initiator was added to the flask with a syringe. 15 minutes after the addition of potassium persulfate, 22.2 parts of a 2.0% aqueous solution of tetramethylethylenediamine as a polymerization accelerator was added by a syringe to start the polymerization reaction.
Four hours after adding potassium persulfate as a polymerization initiator, 4.4 parts of a 2.5% aqueous solution of potassium persulfate as a polymerization initiator was added to the flask, and tetramethylethylenediamine as a polymerization accelerator was further added. By adding 11.1 parts of 2.0% aqueous solution, the temperature was raised to 60 ° C. and maintained at 60 ° C. to proceed the polymerization reaction. After 3 hours from the addition of the polymerization initiator, the flask was opened to the air to stop the polymerization reaction, and the acid functional group-containing monomer and the molar equivalent of the monomer unit represented by the general formula (1) were added. Lithium hydroxide was added as an 8% aqueous solution, and the polymerization product was adjusted to pH 7.0 while stirring at a temperature of 80 ° C. for 6 hours. Then, the polymerization product was coagulated with n-butanol and the solid content was recovered to obtain a water-soluble polymer A. The weight average molecular weight and electrolytic solution swelling degree of this polymer A were measured. The content of compound X (at least one of acetic acid and acetate) relative to the solid content of polymer A was measured. The results are shown in Table 1. Further, with respect to the obtained polymer A, the content ratio of each monomer unit was measured using 1 H-NMR. The results are shown in Table 4.
＜重合体Ｂの調製＞
　撹拌機付き５ＭＰａ耐圧容器Ａに、芳香族単量体としてのスチレン３．１５部と、脂肪族共役ジエン単量体としての１，３－ブタジエン１．６６部と、その他の単量体としてのメタクリル酸０．１９部と、乳化剤としてのラウリル硫酸ナトリウム０．２部と、イオン交換水２０部と、重合開始剤としての過硫酸カリウム０．０３部と、を入れ、十分に撹拌した後、６０℃に加温して重合を開始させ、６時間反応させてシード粒子を得た。
　上記の反応後、７５℃に加温し、芳香族単量体としてのスチレン５８．８５部と、脂肪族共役ジエン単量体としての１，３－ブタジエン３４．３４部と、その他の単量体としてのメタクリル酸０．８１部、連鎖移動剤としてのｔｅｒｔ－ドデシルメルカプタン０．２５部と、乳化剤としてのラウリル硫酸ナトリウム０．３５部と、を入れた別の容器Ｂから、これらの混合物の耐圧容器Ａへの添加を開始し、これと同時に、重合開始剤として過硫酸カリウム１部の耐圧容器Ａへの添加を開始することで２段目の重合を開始した。
　また、２段目の重合を開始から４時間後（単量体組成物全体のうち７０％添加後）、耐圧容器Ａに、その他の単量体としての２－ヒドロキシエチルアクリレート１部を、１時間半に亘って加えた。
　すなわち、単量体組成物全体としては、芳香族ビニル単量体としてのスチレン６２部と、脂肪族共役ジエン単量体としての１，３－ブタジエン３６部と、その他の単量体としてのメタクリル酸１部と、その他の単量体としての２－ヒドロキシエチルアクリレート１部とを用いた。
　２段目の重合開始から５時間半後、これら単量体組成物を含む混合物の全量添加が完了し、その後、さらに８５℃に加温して６時間反応させた。
　重合転化率が９７％になった時点で冷却し反応を停止した。この重合物を含む混合物に、５％水酸化ナトリウム水溶液を添加して、ｐＨ８に調整した。その後、加熱減圧蒸留によって未反応単量体の除去を行った。さらにその後冷却し、粒子状の（水分散体型の）重合体Ｂを得た。 <Preparation of Polymer B>
In a 5 MPa pressure vessel A equipped with a stirrer, 3.15 parts of styrene as an aromatic monomer, 1.66 parts of 1,3-butadiene as an aliphatic conjugated diene monomer, and other monomers After adding 0.19 parts of methacrylic acid, 0.2 part of sodium lauryl sulfate as an emulsifier, 20 parts of ion-exchanged water, and 0.03 part of potassium persulfate as a polymerization initiator, and thoroughly stirring, Polymerization was initiated by heating to 60 ° C., and reaction was performed for 6 hours to obtain seed particles.
After the above reaction, the mixture was heated to 75 ° C., 58.85 parts of styrene as an aromatic monomer, 34.34 parts of 1,3-butadiene as an aliphatic conjugated diene monomer, and other mono From a separate container B containing 0.81 part of methacrylic acid as a body, 0.25 part of tert-dodecyl mercaptan as a chain transfer agent and 0.35 part of sodium lauryl sulfate as an emulsifier, a mixture of these The second stage polymerization was started by starting the addition to the pressure vessel A and at the same time, adding 1 part of potassium persulfate as a polymerization initiator to the pressure vessel A.
Also, 4 hours after the initiation of the second-stage polymerization (after adding 70% of the total monomer composition), 1 part of 2-hydroxyethyl acrylate as another monomer was placed in a pressure resistant container A. Added over half an hour.
That is, as a whole monomer composition, 62 parts of styrene as an aromatic vinyl monomer, 36 parts of 1,3-butadiene as an aliphatic conjugated diene monomer, and methacryl as another monomer. 1 part of acid and 1 part of 2-hydroxyethyl acrylate as other monomer were used.
Five and a half hours after the initiation of the second-stage polymerization, the addition of the entire amount of the mixture containing these monomer compositions was completed, and then the mixture was further heated to 85 ° C. and reacted for 6 hours.
When the conversion of polymerization reached 97%, the reaction was stopped by cooling. A 5% aqueous sodium hydroxide solution was added to the mixture containing the polymer to adjust the pH to 8. Then, the unreacted monomer was removed by heating under reduced pressure. After that, the mixture was cooled to obtain a particulate (water dispersion type) polymer B.
＜二次電池用スラリー組成物の調製＞
　ディスパー付きのプラネタリーミキサーに、電極活物質（炭素系負極活物質：黒鉛系電極活物質）としての比表面積４ｍ2／ｇの人造黒鉛（体積平均粒子径：２４．５μｍ）７６．８部と、電極活物質（金属系負極活物質：シリコン系電極活物質）としてのＳｉＯxを１９．２部と、重合体Ａを固形分相当３．０部とを加え、イオン交換水で固形分濃度５５％に調整し、室温下で６０分回転数４０ｒｐｍにて混合した。次に、イオン交換水で固形分濃度５０％に調整し、さらに１５分回転数４０ｒｐｍにて混合液を得た。
　前記混合液に、重合体Ｂ（固形分相当）１．０部を加え、１０分間３０ｒｐｍにて混合した。これを減圧下で脱泡処理して、流動性の良い二次電池用スラリー組成物を得た。また上述した方法で、二次電池用スラリー組成物の増粘を評価した。結果を表１に示す。 <Preparation of slurry composition for secondary battery>
In a planetary mixer equipped with a disperser, 76.8 parts of artificial graphite (volume average particle diameter: 24.5 μm) having a specific surface area of 4 m 2 / g as an electrode active material (carbon-based negative electrode active material: graphite-based electrode active material) was added. , 19.2 parts of SiO x as an electrode active material (metal-based negative electrode active material: silicon-based electrode active material), and 3.0 parts of polymer A corresponding to the solid content were added, and the solid content concentration was changed with ion-exchanged water. It was adjusted to 55% and mixed at room temperature for 60 minutes at a rotation speed of 40 rpm. Next, the solid content concentration was adjusted to 50% with ion-exchanged water, and a mixed solution was further obtained at a rotation speed of 40 rpm for 15 minutes.
To the mixed solution, 1.0 part of Polymer B (corresponding to solid content) was added and mixed at 30 rpm for 10 minutes. This was defoamed under reduced pressure to obtain a secondary battery slurry composition having good fluidity. Moreover, the thickening of the slurry composition for secondary batteries was evaluated by the method described above. The results are shown in Table 1.
＜負極の製造＞
　上述の二次電池用スラリー組成物を、コンマコーターで、厚さ１８μｍの銅箔（集電体）の上に、乾燥後の膜厚が１０５μｍ、塗布量が１０ｍｇ／ｃｍ2になるように塗布した。この二次電池用スラリー組成物が塗布された銅箔を、０．５ｍ／分の速度で温度７５℃のオーブン内を２分間、さらに温度１２０℃のオーブン内を２分間かけて搬送することにより、銅箔上のスラリー組成物を乾燥させ、負極原反を得た。この負極原反をロールプレスで圧延して、負極合材層の厚みが８０μｍの負極を得た。
　上述した方法で、得られた負極について、負極合材層のピール強度（負極合材層と銅箔（集電体）の密着強度）を評価した。結果を表１に示す。 <Manufacture of negative electrode>
The above slurry composition for a secondary battery was applied on a copper foil (current collector) having a thickness of 18 μm by a comma coater so that the film thickness after drying was 105 μm and the coating amount was 10 mg / cm 2. did. By transporting the copper foil coated with the slurry composition for a secondary battery at a speed of 0.5 m / min in an oven at a temperature of 75 ° C. for 2 minutes and further in an oven at a temperature of 120 ° C. for 2 minutes. Then, the slurry composition on the copper foil was dried to obtain a negative electrode raw material. This negative electrode raw material was rolled by a roll press to obtain a negative electrode having a negative electrode mixture layer thickness of 80 μm.
The peel strength of the negative electrode mixture layer (adhesion strength between the negative electrode mixture layer and the copper foil (current collector)) of the obtained negative electrode was evaluated by the method described above. The results are shown in Table 1.
＜正極の製造＞
　プラネタリーミキサーに、正極活物質としてのスピネル構造を有するＬｉＣｏＯ2：（平均粒子径１４．８μｍ）９５部、正極合材層用バインダーとしてのＰＶＤＦ（ポリフッ化ビニリデン）を固形分相当で３部、導電材としてのアセチレンブラック（平均粒子径：５０ｎｍ）２部、および、溶媒としてのＮ－メチルピロリドン２０部を加えて混合し、リチウムイオン二次電池正極用スラリー組成物（本発明の二次電池用スラリー組成物ではない）を得た。
　得られたリチウムイオン二次電池正極用スラリー組成物を、コンマコーターで、厚さ２０μｍのアルミニウム箔（集電体）上に、乾燥後の膜厚が１００μｍ程度になるように塗布した。このリチウムイオン二次電池正極用スラリー組成物が塗布されたアルミニウム箔を、０．５ｍ／分の速度で温度６０℃のオーブン内を２分間、さらに温度１２０℃のオーブン内を２分間かけて搬送することにより、アルミニウム箔上のリチウムイオン二次電池正極用スラリー組成物を乾燥させ、正極原反を得た。この正極原反をロールプレスで圧延して、正極合材層の厚みが７０μｍの正極を得た。 <Manufacture of positive electrode>
In a planetary mixer, LiCoO 2 having a spinel structure as a positive electrode active material: (average particle diameter 14.8 μm) 95 parts, PVDF (polyvinylidene fluoride) as a binder for the positive electrode mixture layer, 3 parts by solid equivalent, 2 parts of acetylene black (average particle size: 50 nm) as a conductive material, and 20 parts of N-methylpyrrolidone as a solvent were added and mixed to obtain a slurry composition for a lithium ion secondary battery positive electrode (secondary battery of the present invention). Not a slurry composition).
The obtained slurry composition for a lithium ion secondary battery positive electrode was applied by a comma coater onto an aluminum foil (current collector) having a thickness of 20 μm so that the film thickness after drying would be about 100 μm. The aluminum foil coated with the slurry composition for a lithium ion secondary battery positive electrode was conveyed at a rate of 0.5 m / min in an oven at a temperature of 60 ° C. for 2 minutes and further in an oven at a temperature of 120 ° C. for 2 minutes. By doing so, the slurry composition for a lithium ion secondary battery positive electrode on the aluminum foil was dried to obtain a positive electrode raw material. This positive electrode raw material was rolled by a roll press to obtain a positive electrode having a positive electrode mixture layer thickness of 70 μm.
＜セパレータの用意＞
　単層のポリプロピレン製セパレータ（幅６５ｍｍ、長さ５００ｍｍ、厚さ２５μｍ；乾式法により製造；気孔率５５％）を用意した。このセパレータを、５ｃｍ×５ｃｍの正方形に切り抜いて、下記のリチウムイオン二次電池に使用した。 <Preparation of separator>
A single-layer polypropylene separator (width 65 mm, length 500 mm, thickness 25 μm; manufactured by a dry method; porosity 55%) was prepared. This separator was cut out into a 5 cm × 5 cm square and used in the following lithium ion secondary battery.
＜二次電池の作製＞
　電池の外装として、アルミニウム包材外装を用意した。上記正極を、４ｃｍ×４ｃｍの正方形に切り出して、集電体側の表面がアルミニウム包材外装に接するように配置した。次に、正極の正極合材層の面上に、上記正方形のセパレータを配置した。さらに、上記負極を、４．２ｃｍ×４．２ｃｍの正方形に切り出して、これをセパレータ上に、負極合材層側の表面がセパレータに向かい合うよう配置した。その後、露点－４０℃以下の環境下に設置した真空乾燥機にて、ゲージ圧－０．０８ＭＰａ以下、６０℃で１０時間真空乾燥を行った。その後、電解液として濃度１．０ＭのＬｉＰＦ6溶液（溶媒はエチレンカーボネート（ＥＣ）／ジエチルカーボネート（ＤＥＣ）＝１／２（体積比）の混合溶媒、添加剤としてビニレンカーボネート２体積％（溶媒比）含有）を充填した。さらに、アルミニウム包材の開口を密封するために、１５０℃のヒートシールをしてアルミニウム包材外装を閉口し、ラミネートセル型のリチウムイオン二次電池を製造した。上述した方法で、得られたリチウムイオン二次電池について、サイクル特性を評価した。結果を表１に示す。 <Production of secondary battery>
An aluminum packaging exterior was prepared as the exterior of the battery. The above positive electrode was cut into a square of 4 cm × 4 cm and arranged so that the surface of the current collector side was in contact with the aluminum packaging material exterior. Next, the square separator was placed on the surface of the positive electrode mixture layer of the positive electrode. Further, the above negative electrode was cut out into a square of 4.2 cm × 4.2 cm, and this was placed on a separator so that the surface of the negative electrode mixture layer side faces the separator. Then, vacuum drying was carried out at a gauge pressure of −0.08 MPa or less and 60 ° C. for 10 hours using a vacuum dryer installed in an environment having a dew point of −40 ° C. or lower. Then, a LiPF 6 solution having a concentration of 1.0 M was used as an electrolytic solution (the solvent was a mixed solvent of ethylene carbonate (EC) / diethyl carbonate (DEC) = 1/2 (volume ratio), and vinylene carbonate 2% by volume (solvent ratio was used as an additive). ) Contained). Further, in order to seal the opening of the aluminum packaging material, heat sealing was performed at 150 ° C. and the aluminum packaging material exterior was closed to manufacture a laminated cell type lithium ion secondary battery. The lithium ion secondary battery obtained by the method described above was evaluated for cycle characteristics. The results are shown in Table 1.
（実施例２、３および５～７）
　重合体Ａの調製時に、使用する単量体の種類および割合を表１～表２のように変更した以外は、実施例１と同様にして、重合体Ａ、重合体Ｂおよび二次電池用スラリー組成物を調製し、セパレータを用意し、負極、正極および二次電池を製造した。そして、実施例１と同様にして各種評価を行った。結果を表１～表２、表４に示す。 (Examples 2, 3 and 5-7)
For Preparation of Polymer A, Polymer A, Polymer B and Secondary Battery were prepared in the same manner as in Example 1 except that the types and proportions of the monomers used were changed as shown in Tables 1 and 2. A slurry composition was prepared, a separator was prepared, and a negative electrode, a positive electrode, and a secondary battery were manufactured. Then, various evaluations were performed in the same manner as in Example 1. The results are shown in Tables 1 to 2 and 4.
（実施例４）
　重合体Ａの重合開始剤としての過硫酸カリウムの２．５％水溶液の添加量を８．９部から１９．８部に変更し、重合促進剤としてのテトラメチルエチレンジアミンの２．０％水溶液の添加量を２２．２部から４４．４部に変更したこと以外は、実施例１と同様にして、重合体Ａ、重合体Ｂおよび二次電池用スラリー組成物を調製し、セパレータを用意し、負極、正極および二次電池を製造した。そして、実施例１と同様にして各種評価を行った。結果を表１、表４に示す。 (Example 4)
The addition amount of a 2.5% aqueous solution of potassium persulfate as a polymerization initiator for the polymer A was changed from 8.9 parts to 19.8 parts, and a 2.0% aqueous solution of tetramethylethylenediamine as a polymerization accelerator was added. A polymer A, a polymer B and a slurry composition for a secondary battery were prepared and a separator was prepared in the same manner as in Example 1 except that the addition amount was changed from 22.2 parts to 44.4 parts. , A negative electrode, a positive electrode, and a secondary battery were manufactured. Then, various evaluations were performed in the same manner as in Example 1. The results are shown in Tables 1 and 4.
（実施例８）
　重合体Ｂの調製時に、使用する単量体の割合を表２のように変更した以外は、実施例１と同様にして、重合体Ａ、重合体Ｂおよび二次電池用スラリー組成物を調製し、セパレータを用意し、負極、正極および二次電池を製造した。そして、実施例１と同様にして各種評価を行った。結果を表２、表４に示す。 (Example 8)
At the time of preparing the polymer B, a polymer A, a polymer B and a slurry composition for a secondary battery were prepared in the same manner as in Example 1 except that the ratio of the monomers used was changed as shown in Table 2. Then, a separator was prepared, and a negative electrode, a positive electrode, and a secondary battery were manufactured. Then, various evaluations were performed in the same manner as in Example 1. The results are shown in Tables 2 and 4.
（実施例９）
　重合体Ｂの調製を、下記のように、メチルメタクリレート４０部、ｎ－ブチルアクリレート５８．５部、アリルメタクリレート０．５部、およびメタクリル酸１部を使用して行ったこと以外は、実施例１と同様にして、重合体Ａおよび二次電池用スラリー組成物を調製し、セパレータを用意し、負極、正極および二次電池を製造した。そして、実施例１と同様にして各種評価を行った。結果を表２、表４に示す。
＜重合体Ｂの調製＞
　撹拌機付き容器Ｃに、メチルメタクリレート３．１５部と、ｎ－ブチルアクリレート１．６６部と、その他の単量体としてのメタクリル酸０．１９部と、乳化剤としてのラウリル硫酸ナトリウム０．２部と、イオン交換水２０部と、重合開始剤としての過硫酸カリウム０．０３部と、を入れ、十分に撹拌した後、６０℃に加温して重合を開始させ、６時間反応させてシード粒子を得た。
　上記の反応後、７５℃に加温し、メチルメタクリレート３６．８５部と、ｎ－ブチルアクリレート５６．８４部と、その他の単量体としてのメタクリル酸０．８１部と、アリルメタクリリレート０．５部、連鎖移動剤としてのｔｅｒｔ－ドデシルメルカプタン０．２５部と、乳化剤としてのラウリル硫酸ナトリウム０．３５部とを入れた別の容器Ｄから、これらの混合物を、容器Ｃへの添加を開始し、これと同時に、重合開始剤として過硫酸カリウム１部の容器Ｃへの添加を開始することで２段目の重合を開始した。
　２段目の重合開始から５時間半後、これら単量体組成物を含む混合物の全量添加が完了し、その後、さらに８５℃に加温して６時間反応させた。
　重合転化率が９７％になった時点で冷却し反応を停止した。この重合物を含む混合物に、５％水酸化ナトリウム水溶液を添加して、ｐＨ８に調整した。その後、加熱減圧蒸留によって未反応単量体の除去を行った。さらにその後冷却し、粒子状の（水分散体型の）重合体Ｂを得た。 (Example 9)
Polymer B was prepared as follows, except that 40 parts of methyl methacrylate, 58.5 parts of n-butyl acrylate, 0.5 parts of allyl methacrylate, and 1 part of methacrylic acid were used. In the same manner as in 1, a polymer A and a slurry composition for a secondary battery were prepared, a separator was prepared, and a negative electrode, a positive electrode and a secondary battery were manufactured. Then, various evaluations were performed in the same manner as in Example 1. The results are shown in Tables 2 and 4.
<Preparation of Polymer B>
In a container C equipped with a stirrer, 3.15 parts of methyl methacrylate, 1.66 parts of n-butyl acrylate, 0.19 parts of methacrylic acid as another monomer, and 0.2 parts of sodium lauryl sulfate as an emulsifier. Then, 20 parts of ion-exchanged water and 0.03 part of potassium persulfate as a polymerization initiator were added, and after sufficiently stirring, the mixture was heated to 60 ° C. to start the polymerization and reacted for 6 hours to be seeded. The particles were obtained.
After the above reaction, the mixture was heated to 75 ° C., methyl methacrylate (36.85 parts), n-butyl acrylate (56.84 parts), methacrylic acid (0.81 parts) as another monomer, and allyl methacrylate (0.1%). Start adding these mixtures to container C from another container D containing 5 parts, 0.25 parts tert-dodecyl mercaptan as chain transfer agent and 0.35 parts sodium lauryl sulfate as emulsifier. At the same time, the addition of 1 part of potassium persulfate as a polymerization initiator to the container C started the second-stage polymerization.
Five and a half hours after the initiation of the second-stage polymerization, the addition of the entire amount of the mixture containing these monomer compositions was completed, and then the mixture was further heated to 85 ° C. and reacted for 6 hours.
When the conversion of polymerization reached 97%, the reaction was stopped by cooling. A 5% aqueous sodium hydroxide solution was added to the mixture containing the polymer to adjust the pH to 8. Then, the unreacted monomer was removed by heating under reduced pressure. After that, the mixture was cooled to obtain a particulate (water dispersion type) polymer B.
（実施例１０）
　重合体Ｂの調製を、下記のように、１，３－ブタジエン１００部を使用し、反応時間を２０時間として行ったこと以外は、実施例１と同様にして、重合体Ａおよび二次電池用スラリー組成物を調製し、セパレータを用意し、負極、正極および二次電池を製造した。そして、実施例１と同様にして各種評価を行った。結果を表２、表４に示す。
＜重合体Ｂの調製＞
　撹拌機付き５ＭＰａ耐圧容器Ａに、１，３－ブタジエン１００部と、乳化剤としてのラウリル硫酸ナトリウム０．２部と、イオン交換水２０部と、重合開始剤としての過硫酸カリウム０．０３部と、を入れ、十分に撹拌した後、６０℃に加温して重合を開始させ、６時間反応させた。
　上記の反応後、７５℃に加温し、重合開始剤として過硫酸カリウム１部の耐圧容器Ａへの添加し、さらに１８時間反応させた。
　重合転化率が９７％になった時点で冷却し反応を停止した。この重合物を含む混合物に、５％水酸化ナトリウム水溶液を添加して、ｐＨ８に調整した。その後、加熱減圧蒸留によって未反応単量体の除去を行った。さらにその後冷却し、粒子状の（水分散体型の）重合体Ｂを得た。
（実施例１１）
　重合体Ｂの調製を、下記のようにして行ったこと以外は、実施例１と同様にして、重合体Ａおよび二次電池用スラリー組成物を調製し、セパレータを用意し、負極、正極および二次電池を製造した。そして、実施例１と同様にして各種評価を行った。結果を表２、表４に示す。
＜重合体Ｂの調製＞
　撹拌機付き５ＭＰａ耐圧反応に、シクロヘキサン２３３．３部、Ｎ，Ｎ，Ｎ’，Ｎ’－テトラメチルエチレンジアミン６０．０μｍｏｌおよびスチレン２４．０部を添加し、４０℃で撹拌しているところに、ｎ－ブチルリチウム２０００．０μｍｏｌを添加し、５０℃に昇温しながら１時間重合した。引き続き、５５℃を保つように温度制御しながら、反応器にイソプレン７６．０部を１時間にわたり連続的に添加した。イソプレンの添加を完了した後、さらに１時間重合した。
　次いで耐圧容器Ａ内を８５℃とし、さらに２時間反応させ、重合転化率が９８％になった時点でカップリング剤としてジクロロジメチルシラン８２０．０ｍｍｏｌを添加して２時間カップリング反応を行い、スチレン－イソプレンカップリングブロック共重合体を形成させた。その後、メタノール４０００．０μｍｏｌを添加してよく混合し、活性末端を失活させた。反応を停止させ、粒子状の（水分散体型の）重合体Ｂ（ＳＩＳ）を得た。 (Example 10)
Polymer B and secondary battery were prepared in the same manner as in Example 1, except that 100 parts of 1,3-butadiene was used and the reaction time was 20 hours as follows. The slurry composition was prepared, the separator was prepared, and the negative electrode, the positive electrode, and the secondary battery were manufactured. Then, various evaluations were performed in the same manner as in Example 1. The results are shown in Tables 2 and 4.
<Preparation of Polymer B>
In a 5 MPa pressure-resistant container A equipped with a stirrer, 100 parts of 1,3-butadiene, 0.2 part of sodium lauryl sulfate as an emulsifier, 20 parts of ion-exchanged water, and 0.03 part of potassium persulfate as a polymerization initiator. , And after sufficiently stirring, the mixture was heated to 60 ° C. to start polymerization and reacted for 6 hours.
After the above reaction, the mixture was heated to 75 ° C., 1 part of potassium persulfate as a polymerization initiator was added to the pressure resistant container A, and the reaction was further performed for 18 hours.
When the conversion of polymerization reached 97%, the reaction was stopped by cooling. A 5% aqueous sodium hydroxide solution was added to the mixture containing the polymer to adjust the pH to 8. Then, the unreacted monomer was removed by heating under reduced pressure. After that, the mixture was cooled to obtain a particulate (water dispersion type) polymer B.
(Example 11)
A polymer A and a slurry composition for a secondary battery were prepared and a separator was prepared in the same manner as in Example 1 except that the polymer B was prepared as follows. A secondary battery was manufactured. Then, various evaluations were performed in the same manner as in Example 1. The results are shown in Tables 2 and 4.
<Preparation of Polymer B>
Cyclohexane 233.3 parts, N, N, N ′, N′-tetramethylethylenediamine 60.0 μmol and styrene 24.0 parts were added to a 5 MPa pressure resistant reaction equipped with a stirrer, and stirred at 40 ° C., 2000.0 μmol of n-butyllithium was added, and polymerization was carried out for 1 hour while raising the temperature to 50 ° C. Subsequently, 76.0 parts of isoprene was continuously added to the reactor over 1 hour while controlling the temperature so as to maintain 55 ° C. After the addition of isoprene was completed, the polymerization was continued for another hour.
Then, the pressure vessel A is heated to 85 ° C. and further reacted for 2 hours. When the polymerization conversion rate reaches 98%, 820.0 mmol of dichlorodimethylsilane is added as a coupling agent, and the coupling reaction is performed for 2 hours. -Formed an isoprene coupling block copolymer. Then, 4000.0 μmol of methanol was added and mixed well to deactivate the active end. The reaction was stopped, and a particulate (water dispersion type) polymer B (SIS) was obtained.
（実施例１２）
　負極、二次電池多孔膜層用スラリー組成物（セパレータ塗工用組成物）の調製、並びに、セパレータおよび二次電池の製造を下記のように行ったこと以外は、実施例１と同様にして、重合体Ａおよび重合体Ｂを調製し、正極を製造した。そして、実施例１と同様にして各種評価を行った。結果を表２、表４に示す。 (Example 12)
A negative electrode, a secondary battery porous membrane layer slurry composition (separator coating composition) were prepared, and a separator and a secondary battery were manufactured in the same manner as in Example 1 except that the following steps were carried out. , Polymer A and Polymer B were prepared to produce a positive electrode. Then, various evaluations were performed in the same manner as in Example 1. The results are shown in Tables 2 and 4.
＜負極の製造＞
　ディスパー付きのプラネタリーミキサーに、電極活物質（炭素系負極活物質：黒鉛系電極活物質）としての比表面積４ｍ2／ｇの人造黒鉛（体積平均粒子径：２４．５μｍ）７６．８部と、電極活物質（金属系負極活物質：シリコン系電極活物質）としてのＳｉＯxを１９．２部と、カルボキシメチルセルロース（ＣＭＣ）としてＭＡＣ８００ＬＣ（日本製紙ケミカル株式会社）を固形分相当３．０部とを加え、イオン交換水で固形分濃度５５％に調整し、室温下で６０分回転数４０ｒｐｍにて混合した。次に、イオン交換水で固形分濃度４０％に調整し、さらに１５分回転数４０ｒｐｍにて混合液を得た。
　前記混合液に、重合体Ｂ（固形分相当）１．０部を加え、１０分間３０ｒｐｍにて混合した。これを減圧下で脱泡処理して、流動性の良い負極用スラリー組成物を得た。
　上述の負極用スラリー組成物を、コンマコーターで、厚さ１８μｍの銅箔（集電体）の上に、乾燥後の膜厚が１０５μｍ、塗布量が１０ｍｇ／ｃｍ2になるように塗布した。この負極用スラリー組成物が塗布された銅箔を、０．５ｍ／分の速度で温度７５℃のオーブン内を２分間、さらに温度１２０℃のオーブン内を２分間かけて搬送することにより、銅箔上のスラリー組成物を乾燥させ、負極原反を得た。この負極原反をロールプレスで圧延して、負極合材層の厚みが８０μｍの負極を得た。 <Manufacture of negative electrode>
In a planetary mixer equipped with a disperser, 76.8 parts of artificial graphite (volume average particle diameter: 24.5 μm) having a specific surface area of 4 m 2 / g as an electrode active material (carbon-based negative electrode active material: graphite-based electrode active material) was added. , 19.2 parts of SiO x as an electrode active material (metal-based negative electrode active material: silicon-based electrode active material) and MAC800LC (Nippon Paper Chemicals Co., Ltd.) as carboxymethyl cellulose (CMC) equivalent to 3.0 parts of solid content. Was added to adjust the solid content concentration to 55% with ion-exchanged water, and the mixture was mixed at room temperature for 60 minutes at a rotation speed of 40 rpm. Next, the solid content concentration was adjusted to 40% with ion-exchanged water, and a mixed solution was obtained at 15 rpm for 40 minutes.
To the mixed solution, 1.0 part of Polymer B (corresponding to solid content) was added and mixed at 30 rpm for 10 minutes. This was defoamed under reduced pressure to obtain a negative electrode slurry composition having good fluidity.
The above slurry composition for a negative electrode was applied by a comma coater on a copper foil (current collector) having a thickness of 18 μm so that the film thickness after drying was 105 μm and the coating amount was 10 mg / cm 2 . The copper foil coated with the negative electrode slurry composition was conveyed at a rate of 0.5 m / min in an oven at a temperature of 75 ° C. for 2 minutes, and further in an oven at a temperature of 120 ° C. for 2 minutes to obtain copper. The slurry composition on the foil was dried to obtain a negative electrode raw material. This negative electrode raw material was rolled by a roll press to obtain a negative electrode having a negative electrode mixture layer thickness of 80 μm.
＜二次電池多孔膜層用スラリー組成物（セパレータ塗工用組成物）の調製＞
　非導電性微粒子としての酸化アルミニウム（アルミナ）（体積平均粒子径：０．５μｍ）１００部と、分散剤としてのポリカルボン酸アンモニウム（東亜合成製、アロンＡ－６１１４）１．０部と、水とを混合した。水の量は、固形分濃度が５０％となるように調整した。メディアレス分散装置を用いて混合物を処理し、酸化アルミニウムを分散させて、スラリーを得た。得られたスラリーに重合体Ａ（固形分相当）２．０部を添加し、混合した。添加した重合体Ａは、混合物中で溶解した。次いで、重合体Ｂ３．０部（固形分相当）と、濡れ剤としての脂肪族ポリエーテル型のノニオン性界面活性剤０．２部とを添加し、更に水を固形分濃度が４０％になるように添加して、二次電池多孔膜層用スラリー組成物（セパレータ塗工用組成物）を得た。また上述した方法で、二次電池多孔膜層用スラリー組成物（セパレータ塗工用組成物）の増粘を評価した。 <Preparation of slurry composition for secondary battery porous membrane layer (composition for coating separator)>
100 parts of aluminum oxide (alumina) (volume average particle diameter: 0.5 μm) as non-conductive fine particles, 1.0 part of ammonium polycarboxylate (manufactured by Toagosei, Aron A-6114) as a dispersant, and water And were mixed. The amount of water was adjusted so that the solid content concentration was 50%. The mixture was processed using a medialess disperser to disperse aluminum oxide to obtain a slurry. 2.0 parts of Polymer A (equivalent to solid content) was added to the obtained slurry and mixed. The polymer A added was dissolved in the mixture. Next, 3.0 parts of polymer B (corresponding to solid content) and 0.2 part of an aliphatic polyether type nonionic surfactant as a wetting agent are added, and further water is added to have a solid content concentration of 40%. Thus, a secondary battery porous membrane layer slurry composition (separator coating composition) was obtained. Further, the thickening of the slurry composition for a secondary battery porous membrane layer (composition for coating a separator) was evaluated by the method described above.
＜多孔膜層を有するセパレータの作製＞
　湿式法により製造された、単層のポリエチレン製セパレータ基材（幅２５０ｍｍ、長さ１０００ｍ、厚さ１２μｍ）を用意した。そして、再分散させた上記二次電池多孔膜層用スラリー組成物を、セパレータ基材の両方の表面上に、乾燥後の厚さが２．５μｍになるようにグラビアコーター（塗布速度：２０ｍ／分）で塗布した。次いで、セパレータ塗工用組成物を塗布したセパレータ基材を５０℃の乾燥炉で乾燥し、巻き取ることにより、セパレータ基材の両面に多孔膜層（機能層）を有するセパレータを作製した。このセパレータを、５ｃｍ×５ｃｍの正方形に切り抜いて、二次電池の製造に使用した。 <Preparation of Separator Having Porous Membrane Layer>
A single-layer polyethylene separator substrate (width 250 mm, length 1000 m, thickness 12 μm) manufactured by a wet method was prepared. Then, the redispersed slurry composition for a secondary battery porous membrane layer was applied onto both surfaces of the separator substrate so that the thickness after drying was 2.5 μm by a gravure coater (coating speed: 20 m / Min). Next, the separator substrate coated with the composition for coating a separator was dried in a drying oven at 50 ° C. and wound up to produce a separator having a porous membrane layer (functional layer) on both sides of the separator substrate. This separator was cut out into a 5 cm × 5 cm square and used for manufacturing a secondary battery.
＜二次電池の作製＞
　電池の外装として、アルミニウム包材外装を用意した。上記正極を、４ｃｍ×４ｃｍの正方形に切り出して、集電体側の表面がアルミニウム包材外装に接するように配置した。次に、正極の正極合材層の面上に、上記正方形のセパレータを配置した。さらに、上記負極を、４．２ｃｍ×４．２ｃｍの正方形に切り出して、これをセパレータ上に、負極合材層側の表面がセパレータに向かい合うよう配置した。その後、電解液として濃度１．０ＭのＬｉＰＦ6溶液（溶媒はエチレンカーボネート（ＥＣ）／ジエチルカーボネート（ＤＥＣ）＝１／２（体積比）の混合溶媒、添加剤としてビニレンカーボネート２体積％（溶媒比）含有）を充填した。さらに、アルミニウム包材の開口を密封するために、１５０℃のヒートシールをしてアルミニウム包材外装を閉口し、ラミネートセル型のリチウムイオン二次電池を製造した。上述した方法で、得られたリチウムイオン二次電池について、サイクル特性を評価した。 <Production of secondary battery>
An aluminum packaging exterior was prepared as the exterior of the battery. The above positive electrode was cut into a square of 4 cm × 4 cm and arranged so that the surface of the current collector side was in contact with the aluminum packaging material exterior. Next, the square separator was placed on the surface of the positive electrode mixture layer of the positive electrode. Further, the above negative electrode was cut out into a square of 4.2 cm × 4.2 cm, and this was placed on a separator so that the surface of the negative electrode mixture layer side faces the separator. Then, a LiPF 6 solution having a concentration of 1.0 M was used as an electrolytic solution (the solvent was a mixed solvent of ethylene carbonate (EC) / diethyl carbonate (DEC) = 1/2 (volume ratio), and vinylene carbonate 2% by volume (solvent ratio was used as an additive). ) Contained). Further, in order to seal the opening of the aluminum packaging material, heat sealing was performed at 150 ° C. and the aluminum packaging material exterior was closed to manufacture a laminated cell type lithium ion secondary battery. The lithium ion secondary battery obtained by the method described above was evaluated for cycle characteristics.
（実施例１３）
　二次電池用スラリー組成物の調製時に、重合体Ｂを添加しないこと、および、重合体Ａの固形分相当３．０部を４．０部へ変更したこと以外は、実施例１と同様にして、重合体Ａおよび二次電池用スラリー組成物を調製し、セパレータを用意し、負極、正極および二次電池を製造した。そして、実施例１と同様にして各種評価を行った。結果を表２、表４に示す。 (Example 13)
In the same manner as in Example 1 except that the polymer B was not added during the preparation of the slurry composition for a secondary battery and the 3.0 parts corresponding to the solid content of the polymer A was changed to 4.0 parts. Then, a polymer A and a slurry composition for a secondary battery were prepared, a separator was prepared, and a negative electrode, a positive electrode and a secondary battery were manufactured. Then, various evaluations were performed in the same manner as in Example 1. The results are shown in Tables 2 and 4.
（比較例１および２）
　重合体Ａの調製を下記のように行った（使用する単量体の種類および割合を表３のように変更して行った）こと以外は、実施例１と同様にして、重合体Ｂおよび二次電池用スラリー組成物を調製し、セパレータを用意し、負極、正極および二次電池を製造した。そして、実施例１と同様にして各種評価を行った。結果を表３、表４に示す。 (Comparative Examples 1 and 2)
Polymer A and polymer B were prepared in the same manner as in Example 1 except that the polymer A was prepared as follows (the types and proportions of the monomers used were changed as shown in Table 3). A slurry composition for a secondary battery was prepared, a separator was prepared, and a negative electrode, a positive electrode, and a secondary battery were manufactured. Then, various evaluations were performed in the same manner as in Example 1. The results are shown in Tables 3 and 4.
＜重合体Ａの調製（比較例１）＞
　ガラス製１Ｌフラスコに、イオン交換水７８９部を投入して、温度４０℃に加熱し、流量１００ｍＬ／分の窒素ガスでフラスコ内を置換した。次に、アミド基含有単量体としてのアクリルアミド６５部、酸官能基含有単量体としてのアクリル酸１０部、その他の単量体としての２－ヒドロキシエチルアクリレート２０部、メチルアクリレート５部を混合して、フラスコ内に注入した。その後、重合開始剤としての過硫酸カリウムの２．５％水溶液８．９部をシリンジでフラスコ内に添加した。過硫酸カリウムの添加から１５分後に、重合促進剤としてのテトラメチルエチレンジアミンの２．０％水溶液２２．２部をシリンジで添加し、重合反応を開始した。
　重合開始剤としての過硫酸カリウムを添加した４時間後、重合開始剤としての過硫酸カリウムの２．５％水溶液４．４部をフラスコ内に追加し、更に重合促進剤としてのテトラメチルエチレンジアミンの２．０％水溶液１１．１部を追加して、温度を６０℃まで昇温し、６０℃で維持し、重合反応を進めた。重合開始剤の追加から３時間後、フラスコを空気中に開放して重合反応を停止させ、ｐＨ７．０に調整した。その後、ｎ－ブタノールにて重合生成物を凝固させて、固形分を回収し、水溶解型の重合体Ａを得た。 <Preparation of Polymer A (Comparative Example 1)>
789 parts of ion-exchanged water was put into a glass 1 L flask, heated to a temperature of 40 ° C., and the inside of the flask was replaced with nitrogen gas having a flow rate of 100 mL / min. Next, 65 parts of acrylamide as an amide group-containing monomer, 10 parts of acrylic acid as an acid functional group-containing monomer, 20 parts of 2-hydroxyethyl acrylate as another monomer, and 5 parts of methyl acrylate are mixed. Then, it was injected into the flask. Then, 8.9 parts of a 2.5% aqueous solution of potassium persulfate as a polymerization initiator was added to the flask with a syringe. 15 minutes after the addition of potassium persulfate, 22.2 parts of a 2.0% aqueous solution of tetramethylethylenediamine as a polymerization accelerator was added by a syringe to start the polymerization reaction.
Four hours after adding potassium persulfate as a polymerization initiator, 4.4 parts of a 2.5% aqueous solution of potassium persulfate as a polymerization initiator was added to the flask, and tetramethylethylenediamine as a polymerization accelerator was further added. By adding 11.1 parts of 2.0% aqueous solution, the temperature was raised to 60 ° C. and maintained at 60 ° C. to proceed the polymerization reaction. Three hours after the addition of the polymerization initiator, the flask was opened to the air to stop the polymerization reaction, and the pH was adjusted to 7.0. Then, the polymerization product was coagulated with n-butanol and the solid content was recovered to obtain a water-soluble polymer A.
＜重合体Ａの調製（比較例２）＞
　上記比較例１に示す重合体Ａの調製方法において、アミド基含有単量体としてのアクリルアミド６５部をアクリルアミド３０部に変更し、酸官能基含有単量体としてのアクリル酸１０部をアクリル酸５部に変更し、その他の単量体としての２－ヒドロキシエチルアクリレート２０部をそのままとし、その他の単量体としてのメチルアクリレート５部をｎ－ブチルアクリレート４５部に変更したこと以外は、比較例１と同様の方法で、水溶解型の重合体Ａを調製した。 <Preparation of Polymer A (Comparative Example 2)>
In the method for preparing the polymer A shown in Comparative Example 1 above, 65 parts of acrylamide as an amide group-containing monomer was changed to 30 parts of acrylamide, and 10 parts of acrylic acid as an acid functional group-containing monomer was replaced with acrylic acid 5 parts. Comparative Example, except that 20 parts of 2-hydroxyethyl acrylate as the other monomer was left unchanged and 5 parts of methyl acrylate as the other monomer was changed to 45 parts of n-butyl acrylate. A water-soluble polymer A was prepared in the same manner as in 1.
　なお、以下に示す表１～３中、
　「ＡＡｍ」は、アクリルアミドを示し、
　「ＡＡ」は、アクリル酸を示し、
　「ＶＡ」は、酢酸ビニルを示し、
　「ＨＥＡ」は、２－ヒドロキシエチルアクリレートを示し、
　「膨潤度」は、電解液膨潤度を示し、
　「Ｍｗ」は、重量平均分子量を示し、
　「ＬＡ」は、酢酸リチウムを示し、
　「ＭＡ」は、メチルアクリレートを示し、
　「ＢＡ」は、ｎ－ブチルアクリレートを示し、
　「ＢＤ」は、１，３－ブタジエンを示し、
　「ＩＰ」は、イソプレンを示し、
　「ＳＴ」は、スチレンを示し、
　「ＭＡＡ」は、メタクリル酸を示し、
　「ＭＭＡ」は、メチルメタクリレートを示し、
　「ＡＭＡ」は、アリルメタクリレートを示し、
　「ＡＧ」は、人造黒鉛を示し、
　「銅箔コート」は、「銅箔に負極用スラリー組成物をコート」したことを示し、
　「セパレータコート」は、「ポリエチレン製セパレータ基材に多孔膜層用スラリー組成物をコート」したことを示し、
　「ＬＩＢ」は、リチウムイオン二次電池を示し、
　「ＡＡｍ単位」は、アクリルアミド単位を示し、
　「ＡＡ単位」は、アクリル酸単位を示し、
　「ＨＥＡ単位」は、２－ヒドロキシエチルアクリレート単位を示し、
　「ＭＡ単位」は、メチルアクリレート単位を示し、
　「ＢＡ単位」は、ｎ－ブチルアクリレート単位を示す。 In Tables 1 to 3 below,
“AAm” indicates acrylamide,
“AA” indicates acrylic acid,
“VA” indicates vinyl acetate,
“HEA” means 2-hydroxyethyl acrylate,
"Swelling degree" indicates the degree of swelling of the electrolytic solution,
"Mw" indicates a weight average molecular weight,
“LA” represents lithium acetate,
“MA” represents methyl acrylate,
“BA” represents n-butyl acrylate,
“BD” represents 1,3-butadiene,
"IP" indicates isoprene,
"ST" indicates styrene,
“MAA” indicates methacrylic acid,
“MMA” means methyl methacrylate,
"AMA" means allyl methacrylate,
"AG" indicates artificial graphite,
“Copper foil coat” indicates that “a copper foil is coated with the negative electrode slurry composition”,
"Separator coat" means that "a polyethylene separator base material is coated with a slurry composition for a porous membrane layer",
“LIB” indicates a lithium ion secondary battery,
“AAm unit” indicates an acrylamide unit,
"AA unit" means an acrylic acid unit,
“HEA unit” refers to a 2-hydroxyethyl acrylate unit,
“MA unit” indicates a methyl acrylate unit,
"BA unit" indicates an n-butyl acrylate unit.
Figure JPOXMLDOC01-appb-T000012
Figure JPOXMLDOC01-appb-T000012
Figure JPOXMLDOC01-appb-T000013
Figure JPOXMLDOC01-appb-T000013
Figure JPOXMLDOC01-appb-T000014
Figure JPOXMLDOC01-appb-T000014
Figure JPOXMLDOC01-appb-T000015
Figure JPOXMLDOC01-appb-T000015
　上述の表１～３の実施例１～１３および比較例１および２より、所定の重合体Ａおよび溶媒を含むバインダー組成物を用いれば、サイクル特性に優れる二次電池を作製可能であることが分かる。 From Examples 1 to 13 and Comparative Examples 1 and 2 in Tables 1 to 3 described above, it is possible to manufacture a secondary battery having excellent cycle characteristics by using the binder composition containing the predetermined polymer A and the solvent. I understand.
　本発明によれば、サイクル特性に優れる二次電池を作製可能な二次電池用バインダー組成物を提供することができる。
　また、本発明によれば、サイクル特性に優れる二次電池を作製可能な二次電池用スラリー組成物を提供することができる。
　また、本発明によれば、サイクル特性に優れる二次電池を作製可能な二次電池用機能層を提供することができる。
　また、本発明によれば、サイクル特性に優れる二次電池を作製可能な二次電池用電極層を提供することができる。
　また、本発明によれば、サイクル特性に優れる二次電池を提供することができる。
　また、本発明によれば、サイクル特性に優れる二次電池を作製可能な二次電池用バインダー組成物を効率良く製造することができる。
　さらに、本発明によれば、サイクル特性に優れる二次電池を作製可能な二次電池用機能層を効率良く製造することができる。 ADVANTAGE OF THE INVENTION According to this invention, the binder composition for secondary batteries which can produce the secondary battery excellent in cycling characteristics can be provided.
Further, according to the present invention, it is possible to provide a slurry composition for a secondary battery, which can produce a secondary battery having excellent cycle characteristics.
Further, according to the present invention, it is possible to provide a functional layer for a secondary battery, which enables the production of a secondary battery having excellent cycle characteristics.
In addition, according to the present invention, it is possible to provide an electrode layer for a secondary battery, which can produce a secondary battery having excellent cycle characteristics.
Moreover, according to the present invention, a secondary battery having excellent cycle characteristics can be provided.
Further, according to the present invention, a binder composition for a secondary battery capable of producing a secondary battery having excellent cycle characteristics can be efficiently produced.
Further, according to the present invention, it is possible to efficiently manufacture a secondary battery functional layer capable of manufacturing a secondary battery having excellent cycle characteristics.

Claims (14)

  1. 　水溶解型の重合体Ａおよび溶媒を含む二次電池用バインダー組成物であって、
    　前記重合体Ａが、アミド基含有単量体単位、酸官能基含有単量体単位、および下記一般式（１）で表される単量体単位を含む、二次電池用バインダー組成物。
    Figure JPOXMLDOC01-appb-C000001
     （一般式（１）中、Ｒ1は、化学的な単結合、メチレン基、エチレン基、１，２－プロピレン基、または１，３－プロピレン基を表し、Ｒ2およびＲ3は、それぞれ独立して、水素原子、メチル基、エチル基、プロピル基、またはイソプロピル基を表す。）     A binder composition for a secondary battery, comprising a water-soluble polymer A and a solvent,
    A binder composition for a secondary battery, wherein the polymer A contains an amide group-containing monomer unit, an acid functional group-containing monomer unit, and a monomer unit represented by the following general formula (1).
    Figure JPOXMLDOC01-appb-C000001
     (In the general formula (1), R 1 represents a chemical single bond, a methylene group, an ethylene group, a 1,2-propylene group, or a 1,3-propylene group, and R 2 and R 3 are each independently. And represents a hydrogen atom, a methyl group, an ethyl group, a propyl group, or an isopropyl group.)
  2. 　下記一般式（２）で表される化合物Ｘをさらに含み、
    　前記重合体Ａの固形分に対する前記化合物Ｘの含有割合が１００質量ｐｐｍ以上である、請求項１に記載の二次電池用バインダー組成物。
    Figure JPOXMLDOC01-appb-C000002
     （一般式（２）中、Ｘは、水素原子またはアルカリ金属原子を表し、Ｒ4は、炭素数１～５のアルキル基を表す。）     Further comprising a compound X represented by the following general formula (2),
    The binder composition for a secondary battery according to claim 1, wherein the content ratio of the compound X with respect to the solid content of the polymer A is 100 mass ppm or more.
    Figure JPOXMLDOC01-appb-C000002
     (In the general formula (2), X represents a hydrogen atom or an alkali metal atom, and R 4 represents an alkyl group having 1 to 5 carbon atoms.)
  3. 　前記重合体Ａの重量平均分子量が１００万以上である、請求項１または２に記載の二次電池用バインダー組成物。 The binder composition for a secondary battery according to claim 1 or 2, wherein the weight average molecular weight of the polymer A is 1,000,000 or more.
  4. 　前記重合体Ａの電解液膨潤度が１００質量％以上１５０質量％以下である、請求項１～３のいずれかに記載の二次電池用バインダー組成物。 The binder composition for a secondary battery according to any one of claims 1 to 3, wherein the polymer A has a degree of swelling of an electrolytic solution of 100% by mass or more and 150% by mass or less.
  5. 　前記重合体Ａは、前記アミド基含有単量体単位を２０質量％以上６０質量％以下含み、前記酸官能基含有単量体単位を１０質量％以上４５質量％以下含み、前記一般式（１）で表される単量体単位を５質量％以上４０質量％以下含む、請求項１～４のいずれかに記載の二次電池用バインダー組成物。 The polymer A contains 20% by mass or more and 60% by mass or less of the amide group-containing monomer unit, 10% by mass or more and 45% by mass or less of the acid functional group-containing monomer unit, and has the general formula (1 5. The binder composition for a secondary battery according to claim 1, which contains 5% by mass or more and 40% by mass or less of the monomer unit represented by the formula (4).
  6. 　水分散体型の重合体Ｂをさらに含み、
    　前記重合体Ｂが、脂肪族共役ジエン単量体単位を１０質量％以上９０質量％以下含み、芳香族単量体単位を１０質量％以上９０質量％以下含む、請求項１～５のいずれかに記載の二次電池用バインダー組成物。     Further comprising an aqueous dispersion type polymer B,
    The polymer B contains an aliphatic conjugated diene monomer unit in an amount of 10% by mass or more and 90% by mass or less and an aromatic monomer unit in an amount of 10% by mass or more and 90% by mass or less. The binder composition for a secondary battery according to 1.
  7. 　請求項１～６のいずれかに記載の二次電池用バインダー組成物を含む、二次電池用スラリー組成物。 A slurry composition for a secondary battery, comprising the binder composition for a secondary battery according to any one of claims 1 to 6.
  8. 　非導電性微粒子をさらに含む、請求項７に記載の二次電池用スラリー組成物。 The secondary battery slurry composition according to claim 7, further comprising non-conductive fine particles.
  9. 　電極活物質をさらに含む、請求項７に記載の二次電池用スラリー組成物。 The secondary battery slurry composition according to claim 7, further comprising an electrode active material.
  10. 　基材上に、請求項７～９のいずれかに記載の二次電池用スラリー組成物を用いて形成された、二次電池用機能層。 A functional layer for a secondary battery, which is formed on the base material by using the slurry composition for a secondary battery according to any one of claims 7 to 9.
  11. 　集電体上に、請求項９に記載の二次電池用スラリー組成物を用いて形成された、二次電池用電極層。 An electrode layer for a secondary battery, which is formed on the current collector by using the slurry composition for a secondary battery according to claim 9.
  12. 　正極、負極、セパレータおよび電解液を備える二次電池であって、前記正極、前記負極および前記セパレータのいずれか１つ以上が、請求項１０に記載の二次電池用機能層を有する、二次電池。 A secondary battery comprising a positive electrode, a negative electrode, a separator and an electrolytic solution, wherein any one or more of the positive electrode, the negative electrode and the separator has a functional layer for a secondary battery according to claim 10. battery.
  13. 　アミド基含有単量体単位、酸官能基含有単量体単位、および下記一般式（１）で表される単量体単位を含む水溶解型の重合体Ａ、並びに、溶媒を含む二次電池用バインダー組成物を製造する二次電池用バインダー組成物の製造方法であって、
    　アミド基含有単量体、酸官能基含有単量体、および下記一般式（３）で表される単量体を共重合して、共重合体を得る共重合工程と、
    　前記共重合体をけん化して、前記重合体Ａを得るけん化工程とを含む、二次電池用バインダー組成物の製造方法。
    Figure JPOXMLDOC01-appb-C000003
     （一般式（１）中、Ｒ1は、化学的な単結合、メチレン基、エチレン基、１，２－プロピレン基、または１，３－プロピレン基を表し、Ｒ2およびＲ3は、それぞれ独立して、水素原子、メチル基、エチル基、プロピル基、またはイソプロピル基を表す。）
    Figure JPOXMLDOC01-appb-C000004
     （一般式（３）中、Ｒ1は、化学的な単結合、メチレン基、エチレン基、１，２－プロピレン基、または１，３－プロピレン基を表し、Ｒ4は、炭素数１～５のアルキル基を表す。）     A secondary battery containing a water-soluble polymer A containing an amide group-containing monomer unit, an acid functional group-containing monomer unit, and a monomer unit represented by the following general formula (1), and a solvent: A method for producing a binder composition for a secondary battery, comprising:
    A copolymerization step of copolymerizing an amide group-containing monomer, an acid functional group-containing monomer, and a monomer represented by the following general formula (3) to obtain a copolymer,
    A method for producing a binder composition for a secondary battery, comprising a saponification step of saponifying the copolymer to obtain the polymer A.
    Figure JPOXMLDOC01-appb-C000003
     (In the general formula (1), R 1 represents a chemical single bond, a methylene group, an ethylene group, a 1,2-propylene group, or a 1,3-propylene group, and R 2 and R 3 are each independently. And represents a hydrogen atom, a methyl group, an ethyl group, a propyl group, or an isopropyl group.)
    Figure JPOXMLDOC01-appb-C000004
     (In the general formula (3), R 1 represents a chemical single bond, a methylene group, an ethylene group, a 1,2-propylene group or a 1,3-propylene group, and R 4 represents a carbon number of 1 to 5 Represents the alkyl group of.)
  14. 　基材上に、請求項７～９のいずれかに記載の二次電池用スラリー組成物を塗布する塗布工程と、
    　前記塗布工程において塗布された二次電池用スラリー組成物を真空乾燥する真空乾燥工程と、を含む二次電池用機能層の製造方法。     A coating step of coating the secondary battery slurry composition according to any one of claims 7 to 9 on a substrate;
    A method for producing a functional layer for a secondary battery, comprising: a vacuum drying step of vacuum-drying the secondary battery slurry composition applied in the applying step.
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